Resource Timing

Editor's Draft December 13, 2013

This version:
http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/ResourceTiming/Overview.html
Latest version:
http://www.w3.org/TR/resource-timing/
Latest Editor's Draft:
http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/ResourceTiming/Overview.html
Previous versions:
http://dvcs.w3.org/hg/webperf/raw-file/9f30b23d0d99/specs/ResourceTiming/Overview.html
Editors:
Jatinder Mann, Microsoft Corp.,
Arvind Jain, Google Inc.,
Zhiheng Wang, Google Inc. (Until July 2012)
Anderson Quach, Microsoft Corp. (Until March 2011)

Abstract

This specification defines an interface for web applications to access the complete timing information for resources in a document.

Status of this document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This is a work in progress and may change without any notices.

Please send comments to public-web-perf@w3.org (archived) with [ResourceTiming] at the start of the subject line.

This document is produced by the Web Performance Working Group. The Web Performance Working Group is part of the Rich Web Clients Activity in the W3C Interaction Domain.

You can find the latest Editor's Draft of this document in the W3C's Mercurial repository, which is updated on a regular basis.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

Implementers should be aware that this document is not stable. Implementers who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways. Vendors interested in implementing this document before it eventually reaches the Candidate Recommendation stage should join the aforementioned mailing lists and take part in the discussions.

Table of Contents

  1. 1 Introduction
  2. 2 Conformance requirements
  3. 3 Terminology
  4. 4 Resource Timing
    1. 4.1 Introduction
    2. 4.2 Resources Included in the PerformanceResourceTiming Interface
    3. 4.3 The PerformanceResourceTiming Interface
    4. 4.4 Extensions to the Performance Interface
    5. 4.5 Cross-origin Resources
    6. 4.6 Vendor Prefixes
  5. 5 Process
    1. 5.1 Processing Model
    2. 5.2 Monotonic Clock
  6. 6 Privacy and Security
  7. Acknowledgements
  8. References

1 Introduction

This section is non-normative.

User latency is an important quality benchmark for Web Applications. While JavaScript-based mechanisms can provide comprehensive instrumentation for user latency measurements within an application, in many cases, they are unable to provide a complete end-to-end latency picture. While Navigation Timing 2 [NavigationTiming2] addresses part of the problem by providing timing information associated with a navigation, this document introduces the ResourceTiming interface to allow JavaScript mechanisms to collect complete timing information related to resources on a document.

For example, the following JavaScript shows a simple attempt to measure the time it takes to fetch a resource:

<!doctype html>
<html>
  <head>
  </head>
  <body onload="loadResources()">
    <script>
        function loadResources() 
        {
           var start = new Date().getTime();
           var image1 = new Image();
           image1.onload = resourceTiming;
           image1.src = 'http://www.w3.org/Icons/w3c_main.png';

           var resourceTiming = function() {
               var now = new Date().getTime();
               var latency = now - start;
               alert("End to end resource fetch: " + latency);
           };
        } 
    </script>
    <img src="http://www.w3.org/Icons/w3c_home.png">
  </body>
</html>

Though this script can measure the time it takes to fetch a resource, it cannot break down the time spent in various phases. Further, the script cannot easily measure the time it takes to fetch resources described in markup.

To address the need for complete information on user experience, this document introduces the PerformanceResourceTiming interface. This interface allows JavaScript mechanisms to provide complete client-side latency measurements within applications. With this interface, the previous example can be modified to measure a user's perceived load time of a resource.

The following script calculates the amount of time it takes to fetch every resource in the page, even those defined in markup. This example assumes that this page is hosted on http://www.w3.org. One could further measure the amount of time it takes in every phase of fetching a resource with the PerformanceResourceTiming interface.

<!doctype html>
<html>
  <head>
  </head>
  <body onload="loadResources()">
    <script>
       function loadResources() 
       {
          var image1 = new Image();
          image1.onload = resourceTiming;
          image1.src = 'http://www.w3.org/Icons/w3c_main.png';
       }
       
       function resourceTiming() 
       {
           var resourceList = window.performance.getEntriesByType("resource");
           for (i = 0; i < resourceList.length; i++)
           {
              if (resourceList[i].initiatorType == "img") 
              {
                 alert("End to end resource fetch: "+ resourceList[i].responseEnd - resourceList[i].startTime);
              }
           }
       }
    </script>
    <img id="image0" src="http://www.w3.org/Icons/w3c_home.png">
  </body>
</html>

2 Conformance requirements

All diagrams, examples, and notes in this specification are non-normative, as are all sections explicitly marked non-normative. Everything else in this specification is normative.

The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in the normative parts of this document are to be interpreted as described in RFC2119. For readability, these words do not appear in all uppercase letters in this specification. [RFC2119]

Requirements phrased in the imperative as part of algorithms (such as "strip any leading space characters" or "return false and abort these steps") are to be interpreted with the meaning of the key word ("must", "should", "may", etc) used in introducing the algorithm.

Some conformance requirements are phrased as requirements on attributes, methods or objects. Such requirements are to be interpreted as requirements on user agents.

Conformance requirements phrased as algorithms or specific steps may be implemented in any manner, so long as the end result is equivalent. (In particular, the algorithms defined in this specification are intended to be easy to follow, and not intended to be performant.)

The IDL fragments in this specification must be interpreted as required for conforming IDL fragments, as described in the Web IDL specification. [Web IDL]

3 Terminology

The construction "a Foo object", where Foo is actually an interface, is sometimes used instead of the more accurate "an object implementing the interface Foo".

The term DOM is used to refer to the API set made available to scripts in Web applications, and does not necessarily imply the existence of an actual Document object or of any other Node objects as defined in the DOM Core specifications. [DOM3CORE]

A DOM attribute is said to be getting when its value is being retrieved (such as by author script), and is said to be setting when a new value is assigned to it.

The term "JavaScript" is used to refer to ECMA262, rather than the official term ECMAScript, since the term JavaScript is more widely known. [ECMA262]

Throughout this work, all time values are measured in milliseconds since the start of navigation of the document. For example, the start of navigation of the document occurs at time 0. The term current time refers to the number of milliseconds since the start of navigation of the document until the current moment in time. This definition of time is based on the High Resolution Time specification [High Resolution Time] and is different from the definition of time used in the Navigation Timing specification [Navigation Timing], where time is measured in milliseconds since midnight of January 1, 1970 (UTC).

4 Resource Timing

4.1 Introduction

This section is non-normative.

The PerformanceResourceTiming interface facilitates timing measurement of downloadable resources on the root page. For example, this interface is available for XMLHttpRequest objects [XMLHttpRequest], HTML elements [HTML5] such as iframe, img, script, object, embed, and link with the link type of stylesheet, and SVG elements [SVG] such as svg.

Note

The audio and video elements are specifically covered in the Resource Timing Level 2 specification and not in this version of the specification.

The term "resource" is also used to refer to these elements in this work.

4.2 Resources Included in the PerformanceResourceTiming Interface

All resources fetched by the current browsing context must be included as PerformanceResourceTiming objects in the Performance Timeline of the current browsing context. Resources that are retrieved from relevant application caches or local resources must be included as PerformanceResourceTiming objects in the Performance Timeline.

The rest of this section is non-normative.

Examples:

The user agent may choose to limit how many resources are included as PerformanceResourceTiming objects in the Performance Timeline. The recommended minimum number of PerformanceResourceTiming objects is 150, though this may be changed by the user agent. setResourceTimingBufferSize can be called to request a change to this limit.

4.3 The PerformanceResourceTiming Interface

interface PerformanceResourceTiming : PerformanceEntry {
  readonly attribute DOMString initiatorType; 
  
  readonly attribute DOMHighResTimeStamp redirectStart;
  readonly attribute DOMHighResTimeStamp redirectEnd;
  readonly attribute DOMHighResTimeStamp fetchStart;
  readonly attribute DOMHighResTimeStamp domainLookupStart;
  readonly attribute DOMHighResTimeStamp domainLookupEnd;
  readonly attribute DOMHighResTimeStamp connectStart;
  readonly attribute DOMHighResTimeStamp connectEnd;
  readonly attribute DOMHighResTimeStamp secureConnectionStart;
  readonly attribute DOMHighResTimeStamp requestStart;
  readonly attribute DOMHighResTimeStamp responseStart;
  readonly attribute DOMHighResTimeStamp responseEnd;
};

The PerformanceResourceTiming interface participates in the Performance Timeline and extends the following attributes of the PerformanceEntry interface:

The name attribute must return the resolved URL of the requested resource. This attribute must not change even if the fetch redirected to a different URL.

The entryType attribute must return the DOMString resource.

The startTime attribute must return a DOMHighResTimeStamp with the time immediately before the user agent starts to queue the resource for fetching. If there are HTTP redirects or equivalent when fetching the resource, and if all the redirects or equivalent are from the same origin as the current document or the timing allow check algorithm passes, this attribute must return the same value as redirectStart. Otherwise, this attribute must return the same value as fetchStart.

The duration attribute must return a DOMHighResTimeStamp equal to the difference between responseEnd and startTime, respectively.

initiatorType attribute

If the initiator is an element, on getting, the initiatorType attribute must return a DOMString with the same value as the localName of that element.

If the initiator is a CSS resource downloaded by the url() syntax, such as @import url() or background: url(), on getting, the initiatorType attribute must return the DOMString "css".

If the initiator is an XMLHttpRequest object, on getting, the initiatorType attribute must return the DOMString "xmlhttprequest".

redirectStart attribute

If there are HTTP redirects or equivalent when fetching the resource and if all the redirects or equivalent are from the same origin as the current document, this attribute must return the starting time of the fetch that initiates the redirect.

If there are HTTP redirects or equivalent when fetching the resource and if any of the redirects are not from the same origin as the current document, but the timing allow check algorithm passes for each redirected resource, this attribute must return the starting time of the fetch that initiates the redirect. Otherwise, this attribute must return zero.

redirectEnd attribute

If there are HTTP redirects or equivalent when fetching the resource and if all the redirects or equivalent are from the same origin as the current document, this attribute must return the time immediately after receiving the last byte of the response of the last redirect.

If there are HTTP redirects or equivalent when fetching the resource and if any of the redirects are not from the same origin as the current document, but the timing allow check algorithm passes for each redirected resource, this attribute must return the time immediately after receiving the last byte of the response of the last redirect. Otherwise, this attribute must return zero.

fetchStart attribute

If there are no HTTP redirects or equivalent, this attribute must return the time immediately before the user agent starts to fetch the resource.

If there are HTTP redirects or equivalent, this attribute must return the time immediately before the user agent starts to fetch the final resource in the redirection.

domainLookupStart attribute

This attribute must return the time immediately before the user agent starts the domain name lookup for the resource. If a persistent connection [RFC 2616] is used or the resource is retrieved from relevant application caches or local resources, this attribute must return the same value as fetchStart.

If the last non-redirected fetch of the resource is not the same origin as the current document, domainLookupStart must return zero unless the timing allow check algorithm passes.

domainLookupEnd attribute

This attribute must return the time immediately after the user agent finishes the domain name lookup for the resource. If a persistent connection [RFC 2616] is used or the resource is retrieved from relevant application caches or local resources, this attribute must return the same value as fetchStart.

If the user agent has the domain information in cache, domainLookupStart and domainLookupEnd represent the times when the user agent starts and ends the domain data retrieval from the cache.

If the last non-redirected fetch of the resource is not the same origin as the current document, domainLookupEnd must return zero unless the timing allow check algorithm passes.

connectStart attribute

This attribute must return the time immediately before the user agent start establishing the connection to the server to retrieve the resource. If a persistent connection [RFC 2616] is used or the resource is retrieved from relevant application caches or local resources, this attribute must return value of domainLookupEnd.

If the last non-redirected fetch of the resource is not the same origin as the current document, connectStart must return zero unless timing allow check algorithm passes.

connectEnd attribute

This attribute must return the time immediately after the user agent finishes establishing the connection to the server to retrieve the resource. If a persistent connection [RFC 2616] is used or the resource is retrieved from relevant application caches or local resources, this attribute must return the value of domainLookupEnd.

If the transport connection fails and the user agent reopens a connection, connectStart and connectEnd should return the corresponding values of the new connection.

connectEnd must include the time interval to establish the transport connection, as well as other time intervals such as SSL handshake and SOCKS authentication.

If the last non-redirected fetch of the resource is not the same origin as the current document, connectEnd must return zero unless the timing allow check algorithm passes.

secureConnectionStart attribute

This attribute is optional. User agents that don't have this attribute available must set it as undefined. When this attribute is available, if the scheme of the current page is HTTPS, this attribute must return the time immediately before the user agent starts the handshake process to secure the current connection. If the secureConnectionStart attribute is available but HTTPS is not used, this attribute must return zero.

If the last non-redirected fetch of the resource is not the same origin as the current document, secureConnectionStart must return zero unless the timing allow check algorithm passes.

requestStart attribute

This attribute must return the time immediately before the user agent starts requesting the resource from the server, or from relevant application caches or from local resources.

If the transport connection fails after a request is sent and the user agent reopens a connection and resend the request, requestStart must return the corresponding values of the new request.

If the last non-redirected fetch of the resource is not the same origin as the current document, requestStart must return zero unless the timing allow check algorithm passes.

responseStart attribute

This attribute must return the time immediately after the user agent receives the first byte of the response from the server, or from relevant application caches or from local resources.

If the last non-redirected fetch of the resource is not the same origin as the current document, responseStart must return zero unless the timing allow check algorithm passes.

responseEnd attribute

This attribute must return the time immediately after the user agent finishes receiving the last byte of the resource from relevant application caches or from local resources.

4.4 Extensions to the Performance Interface

partial interface Performance {
  void clearResourceTimings();
  void setResourceTimingBufferSize(unsigned long maxSize);

  attribute EventHandler onresourcetimingbufferfull;
};

clearResourceTimings method

The method clearResourceTimings clears the buffer used to store the current list of PerformanceResourceTiming resources.

No parameters

No return value

No additional exceptions

setResourceTimingBufferSize method

The setResourceTimingBufferSize method, when invoked, must set the maximum number of PerformanceResourceTiming resources that may be stored in the buffer to the value of the maxSize parameter.

If this method is not called, the user agent should store at least 150 PerformanceResourceTiming resources in the buffer, unless otherwise specified by the user agent.

If the maxSize parameter is less than the number of elements currently stored in the buffer, no elements in the buffer are to be removed. The maxSize parameter will apply only after the clearResourceTimings method is called.

Parameters

in maxSize type of unsigned long

The maxSize parameter sets the maximum number of PerformanceResourceTiming resources that will be stored in the buffer.

No return value

No additional exceptions

onresourcetimingbufferfull attribute

The event handler for the resourcetimingbufferfull event. Immediately after the buffer used to store the list of PerformanceResourceTiming resources becomes full, the User Agent must fire a simple event named resourcetimingbufferfull that bubbles, isn't cancelable, has no default action, at the Performance object.

4.5 Cross-origin Resources

Cross-origin resources must be included as PerformanceResourceTiming objects in the Performance Timeline. If the timing allow check algorithm fails for a cross-origin resource, these attributes of its PerformanceResourceTiming object must be set to zero: redirectStart, redirectEnd, domainLookupStart, domainLookupEnd, connectStart, connectEnd, requestStart, responseStart and secureConnectionStart, if supported by the user agent.

The terms origin and same origin are defined by The HTTP Origin Header. [IETF RFC 6454]

The term cross-origin is used to mean non same origin.

Server-side applications may return the Timing-Allow-Origin HTTP response header to allow the User Agent to fully expose, to the document origin(s) specified, the values of attributes that would have been zero due to the cross-origin restrictions previously specified in this section.

Timing-Allow-Origin Response Header

The Timing-Allow-Origin header indicates whether a resource's timing can be shared based by returning the value of the Origin request header in the response. ABNF:

Timing-Allow-Origin = "Timing-Allow-Origin" ":" origin-list-or-null | "*"

origin-list-or-null is defined by The HTTP Origin Header. [IETF RFC 6454]

The timing allow check algorithm, which checks whether a cross-origin resource's timing information can be shared with the current document, is as follows:

  1. If the HTTP response includes zero or more than one Timing-Allow-Origin header values, return fail and terminate this algorithm.

  2. If the Timing-Allow-Origin header value is the "*" character, return pass and terminate this algorithm.

  3. If the value of Timing-Allow-Origin is not a case-sensitive match for the value of the Origin header [IETF RFC 6454], return fail and terminate this algorithm.

  4. Return pass.

The above algorithm also functions when the ASCII serialization of an origin is the string "null". Typically, this is the case when there are multiple redirects and the initiator is an XMLHttpRequest object.

In practice the origin-list-or-null production is more constrained. Rather than allowing a space-separated list of origins, it is either a single origin or the string "null".

4.6 Vendor Prefixes

Vendor-specific proprietary user agent extensions are discouraged. If such extensions are needed, e.g., for experimental purposes, vendors must use the following extension mechanisms:

If an extension to the initiatorType IDL attribute return value is needed for an experimental initiator type, on getting the initiatorType IDL attribute, vendors MUST return a DOMString that uses the following convention:

[vendorprefix]-[name]

Where,

If the extension is a new timing attribute, it must:

5 Process

5.1 Processing Model

The following graph illustrates the timing attributes defined by the PerformanceResourceTiming interface. Attributes underlined may not be available when fetching resources from different origins. User agents may perform internal processing in between timings, which allow for non-normative intervals between timings.

Resource Timing attributes

  1. Once the Window object of the current document is created, the user agent must create a PerformanceEntryList primary buffer object to store the list of PerformanceResourceTiming resources.
  2. Set the primary buffer to a size of 150, unless otherwise specified by the user agent or set by the setResourceTimingBufferSize method.
  3. For each resource fetched by the current browsing context, perform the following steps:
    1. Create a new PerformanceResourceTiming object and set entryType to the DOMString resource.
    2. Immediately before the user agent starts to queue the resource for retrieval, record the current time in startTime.
    3. Record the initiator of the resource in initiatorType.
    4. Record the resolved URL of the requested resource in name.
    5. If the new resource is to be fetched using HTTP GET or equivalent, immediately before a user agent checks with the relevant application caches, record the current time as fetchStart. Otherwise, immediately before a user agent starts the fetching process, record the current time as fetchStart. Let domainLookupStart, domainLookupEnd, connectStart and connectEnd be the same value as fetchStart.
    6. If the user agent is to reuse the data from another existing or completed fetch initiated from the current document, abort the remaining steps.
    7. If fetching the resource is aborted for any reason, abort the remaining steps.
    8. If the last non-redirected fetch of the resource is not the same origin as the current document and the timing allow check algorithm fails, the user agent must set redirectStart, redirectEnd, domainLookupStart, domainLookupEnd, connectStart, connectEnd, requestStart, responseStart and secureConnectionStart, if supported by the user agent, to zero and go to Step 3.17.
    9. Let domainLookupStart, domainLookupEnd, connectStart and connectEnd be the same value as fetchStart.
    10. If the resource is fetched from the relevant application cache or local resources, including the HTTP cache, go to step 3.15.
    11. If no domain lookup is required, go to step 3.13. Otherwise, immediately before a user agent starts the domain name lookup, record the time as domainLookupStart.
    12. Record the time as domainLookupEnd immediately after the domain name lookup is successfully done. A user agent may need multiple retries before that. If the domain lookup fails, abort the remaining steps.
    13. If a persistent transport connection is used to fetch the resource, let connectStart and connectEnd be the same value of domainLookupEnd. Otherwise, record the time as connectStart immediately before initiating the connection to the server and record the time as connectEnd immediately after the connection to the server or the proxy is established. A user agent may need multiple retries before this time. If a connection can not be established, abort the remaining steps.
    14. If the user agent supports the secureConnectionStart attribute, in step 3.13, a user agent should also carry out these additional steps:
      1. If the scheme of the current resource is HTTPS, the user agent must record the time as secureConnectionStart immediately before the handshake process to secure the connection.
      2. If the scheme of the current resource is not HTTPS, the user agent must set the value of secureConnectionStart to 0.
    15. Immediately before a user agent starts sending the request for the resource, record the current time as requestStart.
    16. Record the time as responseStart immediately after the user agent receives the first byte of the response.
    17. Record the time as responseEnd immediately after receiving the last byte of the response.

      Return to step 3.13 if the user agent fails to send the request or receive the entire response, and needs to reopen the connection.

      Example

      When persistent connection [RFC 2616] is enabled, a user agent may first try to re-use an open connect to send the request while the connection can be asynchronously closed. In such case, connectStart, connectEnd and requestStart should represent timing information collected over the re-open connection.

    18. Record the difference between responseEnd and startTime in duration.
    19. If the fetched resource results in an HTTP redirect or equivalent, then
      1. If the current resource and the redirected resource are not from the same origin as the current document, and the timing allow check algorithm fails for either resource, set redirectStart and redirectEnd to 0. Then, return to step 3.5 with the new resource.
      2. If the value of redirectStart is not set, let it be the value of fetchStart.
      3. Let redirectEnd be the value of responseEnd.
      4. Set all the attributes in the PerformanceResourceTiming object to 0 except startTime, redirectStart, redirectEnd, and initiatorType.
      5. Return to step 3.5 with the new resource.
    20. If the primary buffer is full, discard the PerformanceResourceTiming object, created in step 3.1. Otherwise, add it to the primary buffer. If adding it causes the primary buffer to become full, fire the resourcetimingbufferfull event at the Document.
      1. If the clearResourceTimings method is called in the event handler for the resourcetimingbufferfull event, clear all PerformanceResourceTiming objects in the primary buffer.
      2. If the setResourceTimingBufferSize method is called in the event handler for the resourcetimingbufferfull event, set the maximum size of the primary buffer to the maxSize parameter. If the maxSize parameter is less than the number of elements currently stored in the buffer, no elements in the buffer are to be removed.

5.2 Monotonic Clock

The value of the timing attributes must monotonically increase to ensure timing attributes are not skewed by adjustments to the system clock while fetching the resource. The difference between any two chronologically recorded timing attributes must never be negative. For all resources, including subdocument resources, the user agent must record the system clock at the beginning of the root document navigation and define subsequent timing attributes in terms of a monotonic clock measuring time elapsed from the beginning of the navigation.

6 Privacy and Security

This section is non-normative.

The PerformanceResourceTiming interface exposes timing information for a resource to any web page that has included that resource. To limit the access to the PerformanceResourceTiming interface, the same origin policy is enforced by default and certain attributes are set to zero, as described in Section 4.5 Cross-origin Resources. Resource providers can explicitly allow all timing information to be collected for a resource by adding the Timing-Allow-Origin HTTP response header, which specifies the domains that are allowed to access the timing information.

Statistical fingerprinting is a privacy concern where a malicious web site may determine whether a user has visited a third-party web site by measuring the timing of cache hits and misses of resources in the third-party web site. Though the PerformanceResourceTiming interface gives timing information for resources in a document, the cross-origin restrictions prevent making this privacy concern any worse than it is today using the load event on resources to measure timing to determine cache hits and misses.

Acknowledgements

We would like to sincerely thank Karen Anderson, Darin Fisher, Tony Gentilcore, Nic Jansma, Kyle Scholz, Jonas Sicking, James Simonsen, Steve Souders, Annie Sullivan, Sigbjørn Vik, Jason Weber to acknowledge their contributions to this work.

References

[IETF RFC 2119]
Key words for use in RFCs to Indicate Requirement Levels, Scott Bradner, Author. Internet Engineering Task Force, March 1997. Available at http://www.ietf.org/rfc/rfc2119.txt.
[IETF RFC 2616]
Hypertext Transfer Protocol -- HTTP/1.1, R. Fielding et al., Authors. Internet Engineering Task Force, June 1999. Available at http://www.ietf.org/rfc/rfc2616.txt.
[IETF RFC 6454]
The Web Origin Concept, Adam Barth, Author. Internet Engineering Task Force, December 2011. Available at http://www.ietf.org/rfc/rfc6454.txt.
[IETF RFC 3986]
Uniform Resource Identifier (URI): Generic Syntax, T. Berners-Lee et al, Authors. Internet Engineering Task Force, January 2005. Available at http://www.ietf.org/rfc/rfc3986.txt.
[DOM Level 3 Core]
Document Object Model Level 3 Core Specification, A. Le Hors, et al., Editors. World Wide Web Consortium, 7 April 2004. This version of the Document Object Model Level 3 Core Recommendation is http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407. The latest version of DOM4 is available at http://www.w3.org/TR/dom/.
[ECMA-262]
ECMAScript Language Specification, 5.1 Edition. ECMA International, Standard ECMA-262, June 2011. This version of the ECMAScript Language is available from http://www.ecma-international.org/publications/standards/Ecma-262.htm.
[XMLHttpRequest]
XMLHttpRequest, Anne van Kesteren, Editor. World Wide Web Consortium, January 2012. This version of the XMLHttpRequest specification is http://www.w3.org/TR/2012/WD-XMLHttpRequest-20120117/. The latest version of XMLHttpRequest is available at http://www.w3.org/TR/XMLHttpRequest/.
[HTML5]
HTML5, Ian Hickson, Editor. World Wide Web Consortium, March 2012. This version of the HTML5 is available from http://www.w3.org/TR/html5/. The latest editor's draft is available at http://dev.w3.org/html5/spec/.
[SVG]
Scalable Vector Graphics (SVG) 1.1, Erik Dahlström, et al, Editors. World Wide Web Consortium, August 2011. This version of the SVG specification Recommendation is available from http://www.w3.org/TR/2011/REC-SVG11-20110816/. The latest version of SVG is available at http://www.w3.org/TR/SVG/.
[Navigation Timing 2]
Navigation Timing 2, Jatinder Mann and Arvind Jain, Editors. World Wide Web Consortium, March 2014. This version of the Navigation Timing 2 specification is available from http://www.w3.org/TR/2014/WD-navigation-timing-2-20140325/. The latest version of Navigation Timing is available at http://www.w3.org/TR/navigation-timing-2/.
[Performance Timeline]
Performance Timeline, Jatinder Mann, et al, Editors. World Wide Web Consortium, W3C Recommendation, December 2013. This version of the Performance Timeline specification is available from http://www.w3.org/TR/2013/REC-performance-timeline-20131212/. The latest version of Performance Timeline is available at http://www.w3.org/TR/performance-timeline/.
[High Resolution Time]
High Resolution Time, Jatinder Mann, Editor. W3C Recommendation, World Wide Web Consortium, December 2012. This version of the High Resolution Time specification is available from http://www.w3.org/TR/2012/REC-hr-time-20121217/. The latest version of High Resolution Time is available at http://www.w3.org/TR/hr-time/.
[Web IDL]
Web IDL, Cameron McCormack, Editor. World Wide Web Consortium, April 2012. This version of the Web IDL specification is available from http://www.w3.org/TR/2012/CR-WebIDL-20120419/. The latest version of Web IDL is available at http://www.w3.org/TR/WebIDL/.