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
What is CPS (characters per second)?
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.
What's a good subtitle reading speed?
For adult audiences, around 15 characters per second is comfortable, and about 17 CPS is a widely-used upper cap (Netflix, for example, caps adult subtitles at 17 CPS). Above roughly 20 CPS, most viewers can't keep up. Children's content is set slower.
How is CPS different from words per minute?
Both measure reading speed. CPS counts characters, which is more precise because word length varies between languages; WPM counts words and is a familiar rule of thumb. The checker shows both so you can use whichever your workflow prefers.
Why do my subtitles feel too fast?
Usually the line is too long for the time it's on screen. You can fix it by shortening (condensing) the text, splitting it across more subtitles, or leaving each one on screen a little longer. The checker suggests a minimum on-screen time for any line.
Is reading speed different for children?
Yes. Content aimed at children uses slower reading speeds — often around 9–12 CPS — because younger viewers read more slowly. Adjust your target accordingly.
Can GoLocalise produce broadcast-standard subtitles?
Yes. We create subtitles, closed captions and SDH to the reading-speed, line-length and file-format standards broadcasters and streaming platforms require, in 100+ languages.
Free tools
More free tools & resources
Subtitle converter
Convert and clean SRT, VTT, SBV, TTML and more.
Script time calculator
Estimate recording time and studio cost from your word count.
Usage fee calculator
Estimate voice over usage and licence fees by media and term.
Which service do I need?
Answer a few questions to find the right service for your project.
Localisation glossary
Plain-English definitions of voice over and subtitling terms.
Guides & how-tos
In-depth guides on subtitling, dubbing, voice over and localisation.
Need subtitles done properly?
We translate, time and format subtitles, closed captions and SDH to broadcast standard in 100+ languages.