Check Captions Against EN 301 549 and WCAG 1.2.2
Or paste subtitle text
Options
The limit is not a number you type in: it is read out of a published document, and the report names that document, quotes the sentence it came from, says whether that sentence is a requirement or guidance, and gives the day we last verified it with a link. Pick the document you are answerable to. They do not agree with each other: Netflix counts characters per second and caps a line at 42 characters, while Ofcom and the BBC count words per minute and, on line length, the BBC caps a line at 37. Three of them state no figures at all — 47 CFR §79.1, WCAG 2.2 SC 1.2.2 and EN 301 549, which requires web pages and non-web documents to satisfy that same criterion. Those three require captions to identify who is speaking and to carry non-speech information, and leave every number to the broadcaster; a page that checks them asks whether the file does it, not whether some number is exceeded. They also do not carry the same weight: a defect that reads as a warning against WCAG reads as an error against EN 301 549, because the standard turns that criterion into a shall. Changing this box changes the limit and the citation together, so a report can never carry one document's number under another document's name. Pages that check something only one of these documents states offer only that one.
Which frame rate the timings are counted in. On the format pages this is what MicroDVD needs, because it stores timing as frame numbers. On the frame rate pages it is the rate the file was timed against — the version the subtitles were made for — and the page's second box takes the rate of the video you are going to use them with. 23.976, 24, 25, 29.97, 30, 50, 59.94 and 60 are the common ones. Getting it wrong shifts the whole timeline, and on the frame rate pages it shifts it by a ratio rather than by a fixed amount.
EN 301 549 is the European standard for accessibility requirements in ICT, and about prerecorded captions it says one thing: clause 9.1.2.2 requires web pages, and clause 10.1.2.2 non-web documents, to satisfy WCAG 2.1 Success Criterion 1.2.2 Captions (Prerecorded). It states no requirement of its own beyond that incorporation, and WCAG's own criterion states no numbers — no reading rate, no line length, no duration limits. This page runs every subtitle check it has against either document, which is why it is one page rather than two: the check is the same check, and only the weight of the sentence changes. The file is read in your browser, never uploaded, and is not changed.
The weight is the interesting part, and it is the reason both documents are offered here. The sentence this page applies is stated as a duty by EN 301 549 — shall satisfy — and as guidance by WCAG, whose Understanding document carries the words about identifying who is speaking. The same cue in the same file therefore reads as an error against the European standard and as a warning against the criterion it incorporates. Nothing about the file changed between those two runs. That is a fact about the two documents, and it is worth seeing once.
Because neither document gives figures, four of the five sections of the report will say no limit was given. That is not an empty page. It is the answer to a question people ask before writing a house style: whether the accessibility standard they have to meet says anything about how fast a subtitle may be read or how long it may stay on screen. It does not; those numbers live in broadcaster and platform style guides, which is a different kind of document, and the reports for them say so.
Examples
The same file under EN 301 549
Subtitles
1
00:00:01,000 --> 00:00:03,000
JOHN: I told you not to wait up.
2
00:00:04,000 --> 00:00:07,400
- I know what you did last summer, and I am not going to pretend otherwise.
- Then say it out loud, right here, in front of everybody.
3
00:00:09,000 --> 00:00:09,600
Wait.
4
00:00:11,000 --> 00:00:19,200
MARY: Nothing. It does not matter now.
5
00:00:21,000 --> 00:00:23,000
The quick brown fox jumps over the lazy dog every single morning.
What the report finds
Cues with two speakers and no name — 1 found
Severity Cues Start End Measured Clause
Error 2 00:00:04.000 00:00:07.400 2 items ETSI EN 301 549 v3.2.1 — Accessibility requirements for ICT products and services — 9.1.2.2 Captions (Prerecorded): Where ICT is a web page, it shall satisfy the WCAG 2.1 Success Criterion 1.2.2 Captions (Prerecorded)
What it was checked against
Standard: ETSI EN 301 549 (EU accessibility requirements for ICT)
Where it is stated: 9.1.2.2 Captions (Prerecorded): Where ICT is a web page, it shall satisfy the WCAG 2.1 Success Criterion 1.2.2 Captions (Prerecorded)
Stated as: Requirement
Verified: 2026-10-16
Not checked by this page: 10.1.2.2 Captions (Prerecorded): Where ICT is a non-web document, it shall satisfy the WCAG 2.1 Success Criterion 1.2.2 Captions (Prerecorded)Note the closing line: EN 301 549 handles web pages and non-web documents in two separate clauses that say the same thing about the same criterion. This page applies the one for web pages and names the other under what it did not check, because which of the two applies to you depends on what the file is being published as, and a text file does not say. The citation itself does the rest of the work: the clause number is EN 301 549's, and the sentence being applied is quoted from WCAG, because that is the shape of the standard — it adopts the criterion rather than restating it.
The same bytes under WCAG 2.2 SC 1.2.2
Subtitles
1
00:00:01,000 --> 00:00:03,000
JOHN: I told you not to wait up.
2
00:00:04,000 --> 00:00:07,400
- I know what you did last summer, and I am not going to pretend otherwise.
- Then say it out loud, right here, in front of everybody.
3
00:00:09,000 --> 00:00:09,600
Wait.
4
00:00:11,000 --> 00:00:19,200
MARY: Nothing. It does not matter now.
5
00:00:21,000 --> 00:00:23,000
The quick brown fox jumps over the lazy dog every single morning.
What the report finds
Cues with two speakers and no name — 1 found
Severity Cues Start End Measured Clause
Warning 2 00:00:04.000 00:00:07.400 2 items Understanding Success Criterion 1.2.2: Captions (Prerecorded) — Intent: captions not only include dialogue, but identify who is speaking
What it was checked against
Standard: WCAG 2.2 Success Criterion 1.2.2
Where it is stated: Intent: captions not only include dialogue, but identify who is speaking
Stated as: GuidelineIdentical input, identical cue, identical measurement — and Warning in the severity column rather than Error. That single cell is the argument for having this page rather than two: the change is in the document, and comparing the two runs is the only way to see it. The clause line changes as well, from an EN 301 549 clause number to the Understanding document, because that is where WCAG states it. Neither is more correct than the other; they are the two documents, and the report is telling you which one you asked about.
A name that a dash hides
Subtitles
1
00:00:01,000 --> 00:00:03,000
MARY: It does not matter now.
2
00:00:04,000 --> 00:00:07,000
- JOHN: I told you not to wait up.
- Then say it out loud.
What the report finds
Cues with two speakers and no name — 1 found
Severity Cues Start End Measured Clause
Error 2 00:00:04.000 00:00:07.000 2 items ETSI EN 301 549 v3.2.1 — Accessibility requirements for ICT products and services — 9.1.2.2 Captions (Prerecorded)
This file does name the second speaker — as "- JOHN:" — and it is reported anyway. That is a known limitation of the check, printed here rather than filed away: a name is only recognised when it begins the line, and a dash at the start of the line is read as a change of speaker with no name attached. The fix is to write either "JOHN:" or a bare dash, not both. This example exists because a limitation you can see in an example is easier to work around than one you meet in a report at the end of a delivery.
Frequently asked questions
Why are EN 301 549 and WCAG 1.2.2 checked on the same page?
Because EN 301 549 clause 9.1.2.2 does not state its own requirement for prerecorded captions: it requires web pages to satisfy WCAG 2.1 Success Criterion 1.2.2. Two pages would run the same rules over the same file and produce reports that differ only in the standard named at the top, which is a pair of near-duplicate pages rather than two answers. One page with a choice of document keeps the comparison available where it matters, in the severity and clause columns.
Why does the same cue read as an error under EN 301 549 and a warning under WCAG?
Because the document decides the weight, not the check. EN 301 549 states the requirement with shall satisfy, so the report carries a finding as an error. WCAG's Success Criterion 1.2.2 is a Level A criterion whose normative text does not mention identifying who is speaking — that sentence is in the Understanding document published alongside it, which is informative material — so the report carries the same finding as a warning. Running both takes seconds and is the clearest way to see which document you are actually answerable to.
Which clauses of EN 301 549 apply to subtitles, and which one does this page not check?
Clause 9.1.2.2 applies to web pages and clause 10.1.2.2 to non-web documents; both require satisfying WCAG 2.1 Success Criterion 1.2.2. This page applies the web page clause and lists the non-web one under what it did not check, because which applies depends on how the content is published and a subtitle file does not record that. Selecting this standard and reading that closing line tells you both clauses exist, which is more than a report that quietly picked one would.
Do EN 301 549 and WCAG 1.2.2 state any numbers for subtitle timing or length?
Neither states one. Success Criterion 1.2.2 requires captions to be provided for prerecorded content, and the material around it asks that they identify who is speaking and convey non-speech information; there is no reading rate, no line length, no minimum or maximum duration anywhere in it. EN 301 549 adds nothing numeric on top, since it adopts the criterion rather than restating it. Four of the five sections of this report say as much, and that is the answer to a question people ask before writing a house style.
What does the European Accessibility Act have to do with EN 301 549?
EN 301 549 is the harmonised standard that the European Accessibility Act points at, so it is the document a European service tends to be assessed against rather than WCAG on its own. That is why this page offers it alongside the criterion it incorporates, and why its findings read as errors: the act makes the requirement binding through the standard, where WCAG on its own is a standard a site may choose to meet. The report still describes a file rather than a service, so it stops short of a verdict either way.
Does this page decide whether a service complies with EN 301 549?
No. It reports what one subtitle file contains: how many cues measured the way this page measures them, which clause each finding cites, and what was not checked. EN 301 549 applies to ICT products and services, and a service involves players, interfaces and delivery as well as the caption file. A clean report here means the file did not trip the checks this page runs, which is a narrower statement than the one a compliance decision needs.
What the check looks for
- The report describes a file, not a service. EN 301 549 is the harmonised standard the European Accessibility Act points at, and WCAG 2.2 is a standard a site or a product is assessed against; neither is a statement about one subtitle file, and nothing here concludes that anything complies. What the report states is how many cues measured the way this page measures them, which clause each finding cites, how that clause is stated in the document it came from, and which parts of the documents this page did not check.
- The distinction between the two documents on this page is not decoration. The same cue reads as an error against EN 301 549 and as a warning against WCAG, because one states the requirement as a shall and the other states it in informative material. Which of those you are answerable to depends on where the content is published and who is asking, which is not something a subtitle file can tell us, so the report reports both rather than choosing.
References
- EN 301 549 (ETSI) v3.2.1 — clause 9.1.2.2 Captions (Prerecorded): where ICT is a web page, it shall satisfy the WCAG 2.1 Success Criterion 1.2.2 Captions (Prerecorded). Clause 10.1.2.2 states the same requirement for non-web documents. The standard states nothing of its own about captions beyond that incorporation, so the sentence this page applies is quoted from WCAG and only the clause number is quoted from here.
- WCAG 2.2 Success Criterion 1.2.2 (Captions, Prerecorded), Level A. The criterion requires captions for prerecorded audio content in synchronised media. The sentence about identifying who is speaking is in the Understanding document for it, which is informative rather than normative, and that is why this page records the finding as a warning when WCAG is the document chosen.