Subtitle reading speed checker
Are your subtitles readable? Check a single line, or import a whole .srt or .vtt fileto flag every cue that's too fast. You'll get the reading speed in characters per second (CPS) and words per minute — all checked right in your browser, nothing uploaded.
Paste one subtitle (up to two lines).
Longest line is 44 characters — most guidelines keep lines to ≤ 42.
Need to change formats too? Use the subtitle converter. A quick readability check, not a full subtitle QC — ask our team for subtitles built to your platform's exact spec.
Subtitle reading-speed rules of thumb
~15 CPS is comfortable
A relaxed reading speed for adult audiences — most viewers read this without effort.
~17 CPS is the common cap
A widely-used maximum for adult subtitles; several major platforms set their limit here.
≤ 42 characters per line
Standard maximum line length, over a maximum of two lines, to keep subtitles legible.
Slower for children
Children's content typically targets ~9–12 CPS to match younger reading speeds.
Condense, don't cram
If a line runs too fast, shorten the text or split it across subtitles rather than speeding it up.
Guidance, not gospel
House styles differ. Treat these as a strong starting point and follow your platform's spec.
Frequently asked questions
Characters per second is the standard measure of subtitle reading speed: the number of characters in a subtitle divided by the number of seconds it's on screen. It tells you whether a viewer has time to read the line comfortably before it disappears.
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