Accessibility · official-source review · reviewed 2026-10-10
Most auto-generated captions display too many words per line and too many words per minute to actually read.
Check whether a caption line fits the 32-character line limit and matches comfortable reading speed.
Video creators editing captions for accessibility.
Use the source document or official route that applies to your situation. This guide does not contact another person or verify external information.
Paste one caption line as it appears on screen.
Keep lines under 32 characters for comfortable reading.
Aim for ~160 words per minute or slower for most content.
Split lines at natural phrase boundaries and extend duration if needed.
An 80-character line displayed for 3 seconds is too long and too fast; split it into two lines with more time.
Use your own source and details. The example is not a record about a real person or organization.
Described and Captioned Media Program / W3C WAI · reviewed 2026-10-10
What this source supports: Caption quality guidelines recommend keeping line length around 32 characters per line and reading speed below 180 words per minute for general content.
Source limit: Different content types (education vs children) use different timing targets.
These sources support the statements above. They do not show that every person needs this guide. They do not show a specific result.
This checks character counts and timing. It does not generate captions.
Different content types (education vs children) use different timing targets.
Use current instructions from the responsible organization. This guide is a planning aid, not an official decision or a substitute for qualified advice.
Check caption line length and reading speed against standard guidelines.
This counts characters and estimates WPM. It does not edit captions.
You enter every number yourself. The sources support the method and the limits. They do not produce a result for your specific case. Keep the original documents next to the sheet you build.
The App computes the worked example with your own numbers, in your browser.
APP 1
Check caption line length and reading speed against standard guidelines.
Free · no account · no upload
Open Caption Line CheckerThe App runs in this browser. It does not send or save entries. Copy, download, or print only when you choose.
This guide uses short, direct instructions as an ASD-STE100-style writing target. It is not a formal certification.
Companion App: Caption Line Checker. It runs in this browser and does not upload your entries.
This guide is edited for clarity and checked against the sources it links. It is not a substitute for official instructions or qualified advice. A linked source does not show that every person needs this guide.