Caption reading-speed check
Paste an SRT or WebVTT file and see which captions are too fast to read, which lines are too long, and which cues flash by or overlap. It runs in your browser: the file never leaves your computer.
Paste subtitles or open a file to check them.
How to fix what it finds
- Too fast to read: shorten the wording, or give the cue more time if the speech allows it. Splitting one long cue into two at a natural pause often fixes it.
- Line too long or too many lines: break at a natural phrase boundary, never between an article and its noun.
- On screen too briefly: merge with the next cue or extend its end time a little.
- Overlaps the next cue: end it before the next one starts. If the whole file is early or late, use shift subtitle timing.
More on caption style, timing and line breaks: how to add captions to a video.
Questions
What reading speed should captions have?
Common guidelines put adult captions at about 15 to 20 characters per second, spaces included, with slower speeds for younger audiences or hard material. Your platform or client may have its own rule; set the limit to match it.
How long should a caption line be?
About 32 to 42 characters per line and no more than two lines is a common guideline for widescreen video. Vertical video usually needs shorter lines.
How is characters per second counted here?
Every visible character of the cue, spaces included, divided by how long the cue is on screen. Formatting tags such as <i> are ignored.
Is my file uploaded?
No. The check runs in your browser on this page.
Cutting the video too?
Endroll is an AI video editor for Windows and Mac. Write what the video should say, and it finds the moments in your own footage and builds the cut, captions included. See how it works.