Focusable Elements (Strict) - ally.js Compatibility Table

The following tables show the differences between what browsers consider focusable and what ally.js identifies using strategy: strict.

Note that touch devices (without a physical keyboard) only show elements as tabbable (keyboard focusable), that can be navigated to through the on-screen keyboard (or "virtual keyboard").

Document Elements
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<html>` 2 1	inert -1	inert -1	focusable inert -1 E S	focusable inert -1 E S	tabbable inert 0	tabbable inert 0	tabbable inert 0	inert 0	inert 0	inert -1	inert -1	inert -1	inert -1	inert -1	inert -1	inert -1
`<body>` 3 1	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S	tabbable inert 0 E	tabbable inert 0	tabbable inert 0 E	focusable inert 0 E S	focusable inert 0 E S	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S	focusable inert -1 E S

Label Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<label for="…"> with <input id="…">` 6	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	inert redirecting 0 7	inert redirecting 0 7	inert redirecting 0 7	inert redirecting 0 7	inert redirecting 0	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T
`<label> with nested <input>` 6	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	inert redirecting 0 7	inert redirecting 0 7	inert redirecting 0 7	inert redirecting 0 7	inert redirecting 0	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T	redirecting -1 T

Image Maps
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<input> between <img usemap="#map"> and <img usemap="#map">` 45	tabbable 0	tabbable 0	focusable tabbable 0 44	focusable tabbable 0 44	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	focusable 0	tabbable 0
`<area> child of <map name="#…"> with <object type="image/png" usemap="#…">`	inert 0 R	inert 0 R	focusable inert 0 R	focusable inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R
`<area href="…"> <object type="image/png" usemap="#…" >`	inert 0 R	inert 0 R	focusable inert 0 R	focusable inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R	inert 0 R

Shadow DOM
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`::shadow` 18 19	inert host inert -1 C	inert host inert -1 C	inert -1	inert -1	inert 0	inert 0	inert 0	inert 0	inert 0	inert host inert -1 C	inert -1	inert -1	inert -1	inert -1	inert host inert -1 C	inert -1

Iframe Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<iframe src="…"> without focusable content` 21 22	tabbable focusable 0 S	tabbable focusable 0 S	tabbable focusable 0 E S C	tabbable focusable 0 E S C	focusable 0 C	focusable 0 C	focusable 0 C	focusable 0	focusable 0	tabbable focusable 0 S	tabbable focusable 0 S	tabbable focusable 0 S	tabbable focusable 0 S	tabbable focusable 0 S	focusable 0 S	focusable 0 S
`<iframe src="…"> with SVG document` 21 22	focusable 0 S C	focusable 0 S C	tabbable focusable 0 E S	tabbable focusable 0 E S	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0 S C	focusable 0 S C	focusable 0 S C	focusable 0 S C	focusable 0 S C	focusable 0 S C	focusable 0 S C
`content in <iframe>` 21 22	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M

Object Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<object type="application/x-shockwave-flash" data="…">` 31	focusable 0	focusable 0	focusable -1	focusable -1	inert 0	focusable tabbable 0 32	tabbable 0	tabbable 0	tabbable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0
`<object type="application/x-shockwave-flash" data="…" tabindex="0">` 31	focusable 0	focusable 0	tabbable 0	tabbable 0	inert 0	focusable tabbable 0 32	tabbable 0	tabbable 0	tabbable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0	focusable 0

SVG Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<rect onfocus="">` 33 35	tabbable inert 0 34	tabbable inert 0 34	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	tabbable inert 0 34	tabbable inert 0	tabbable inert 0	tabbable inert 0 34	tabbable inert 0 34	focusable inert 0 34	focusable inert 0 34

SVG Document in Iframe Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`content in <iframe>` 21 22	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M

SVG Document in Embed Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`content in <embed>` 23 24	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M

SVG Document in Object Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`content in <object>` 25 26	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M

Details Element
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<summary> within <details>` 38	tabbable 0	tabbable 0	inert -1	inert -1	inert 0	inert 0	inert 0	inert 0	inert 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	focusable tabbable 0 39	focusable 0	focusable 0
`<summary> within <details tabindex="-1">` 38	tabbable 0	tabbable 0	inert -1	inert -1	inert 0	inert 0	inert 0	inert 0	inert 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	focusable tabbable 0 39	focusable 0	focusable 0
`<a href="…"> within <details open>` 38	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	focusable tabbable 0 39	focusable 0	focusable 0
`<summary> within <details open>` 38	tabbable 0	tabbable 0	inert -1	inert -1	inert 0	inert 0	inert 0	inert 0	inert 0	tabbable 0	tabbable 0	tabbable 0	tabbable 0	focusable tabbable 0 39	focusable 0	focusable 0

Questionable Elements
Element	Chrome		Firefox		IE					Opera	Safari			WebKit Nightly	Chrome Mobile (Android)	Safari (iOS)
Element	47.0	49.0	43.0	46.0	9.0	10.0	11.0	12.10240	13.11082	34.0	6.2	8.0	9.0	602.1	47.0	9.0
`<keygen …>` 47 48	inert null M	inert null M	inert null M 46	inert null M 46	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M	inert null M

Footnotes

The DOM Element Interface is missing the focus method.
The focus event is not emitted upon the element becoming the active element (document.activeElement).
The :focus CSS pseudo class is not set on the element when it is the active element (document.activeElement).
The element becomes the active element (document.activeElement) when an element of contentDocument or the shadowRoot has focus.
Note 1

Considering the <html> and <body> element focusable should have no benefit to a website (unless explicitly made focusable by adding the tabindex attribute), which is why ally.js considers the <html> and <body> element inert.
Note 2

The <html> element itself is not considered focusable, but some browsers may give it focus when focus is passed from browser UI to the document.
Note 3

The <body> element itself is not considered focusable, but it is has focus (i.e. is document.activeElement) if no other element has focus.
Note 6

The activation behavior of the <label> element is not defined beyond »… should match the platform's label behavior.«
Note 7

Internet Explorer redirects focus from <label> to the referenced form control element upon mouse click, but not on script focus via element.focus().
Note 18

Shadow DOM is currently only "properly" supported in Blink based browsers (Chrome, Opera). Firefox exposes the (considerably buggy) development state behind flags.

See Can I Use.
Note 19

Regardless of its own focusable state, an element hosting a Shadow DOM can become the activeElement if an element inside the ShadowRoot has focus. See Shadow DOM - Active Element
Note 21

Technically the content of an iframe can be accessible to script.
Note 22

Because of the Same Origin Policy we can't reliably look inside <iframe>s to determine their content, which is why ally.js considers all <iframe> content inert
Note 23

There is no API to interact with the content document of an <embed> element
Note 24

Because there is no API to dive into the content document of an <embed> element, ally.js considers all <embed> content inert.
Note 25

Technically the content of an <object> element can be accessible to script.
Note 26

Because of the Same Origin Policy we can't reliably look inside <object>s to determine their content, which is why ally.js considers all <object> content inert.
Note 31

The behavior of the <object> element depends on the content it presents. The most common content types used with <object> are SVG and SWF.
Note 32

This element is actually tabbable (keyboard focusable).

But when tabbing to it, the <kbd>Tab</kbd> behavior for the entire document breaks, as focus remains stuck on the browser UI.

This might be related to Trident 1109008.
Note 33

SVG 1.1 does not specify much in respect to accessibility. SVG 2 will bring the tabindex attribute. SVG Tiny 1.2 knows the focusable attribute.
Note 34

By registering a focus event listener the element becomes focusable. Blink 445798, WebKit 140024.

This is undetectable because elements don't provide a list of their registered event handlers.
Note 35

Elements made focusable by way of adding a focus event listener cannot be identified by ally.js
Note 38

The <details> element is specified in HTML 5.1, but not implemented everywhere.
Note 39

This element should be keyboard focusable (tabbable), but is currently only focusable because of WebKit 151767
Note 44

Firefox may hide elements from the document's tabbing sequence if they're enclosed by two images referencing the same image map - Gecko 1116126.
Note 45

This test is not about an element's focusable state, but about potentially content that's potentially hidden from the tabbing sequence.
Note 46

Firefox transforms <keygen> to <select _moz-type="-mozilla-keygen"> while parsing HTML.
Note 47

The <keygen> element is poorly supported, practically never used and has seen intent to deprecate
Note 48

Because the <keygen> element is poorly supported, ally considers all <keygen> elements focus-relevant but not focusable.
Note 52

Focus is redirected to the labeled control.
Note 53

Focus is redirected to the nested labeled control.
Note 78

When this element is the activeElement, the reference element <object usemap="…"> has the following state:
- is not the activeElement in its context
- does not have the :focus CSS pseudo class applied
- does not receive a focus event
Note 79

When this element is the activeElement, the reference element <object usemap="…"> has the following state:
- is not the activeElement in its context
- does not have the :focus CSS pseudo class applied
- receives a focus event

Focusable Elements (Strict) - ally.js Compatibility Table

Footnotes

Note 1

Note 2

Note 3

Note 6

Note 7

Note 18

Note 19

Note 21

Note 22

Note 23

Note 24

Note 25

Note 26

Note 31

Note 32

Note 33

Note 34

Note 35

Note 38

Note 39

Note 44

Note 45

Note 46

Note 47

Note 48

Note 52

Note 53

Note 78

Note 79