Subtitle QC checklist and language limits

Check a subtitle file before you deliver it. Then see the Netflix limits for 52 languages: characters per line, reading speed, duration, gaps, and lines.

Facts checked on 2026.10.13. Sources

QC checklist before delivery

Run these checks on every file before you send it. The numbers are Netflix's. Other buyers set their own, so ask for their guide first. The next section lists the limits for each language.

Reading speed
Divide the characters in each subtitle by the seconds it stays on screen. The result is CPS. Each language has its own upper limit, and children's content has a lower one. Use the CPS calculator for one subtitle, or the SRT validator for a whole file.
Characters per line
Count the characters in the longest line. Most Netflix guides allow 42. Thai allows 35, Chinese and Korean 16, and Japanese 13.
Number of lines
Use two lines at most. Keep the text on one line when it fits.
Minimum and maximum duration
No subtitle may be shorter than 5/6 second (20 frames at 24 fps) or longer than 7 seconds. Japanese is the exception: its minimum is half a second.
Gaps between subtitles
Leave at least 2 frames between two subtitles. Close small gaps instead of leaving them open. See the timing rules. The fix gaps and overlaps tool closes every gap shorter than a limit you set.
Overlaps
A subtitle must not start before the previous one ends. Find every overlap and change one of the two times. The fix gaps and overlaps tool removes them.
Sync and shot changes
Start each subtitle on the first frame of its audio, or within 1 or 2 frames of it. Keep subtitles inside the shot when the dialogue stays inside it.
Line breaks
The Netflix English guide says to break a line after a punctuation mark, before a conjunction, or before a preposition. Do not separate an article from its noun or a first name from a last name. When you have a choice, make the bottom line the longer one. The line breaker tool splits lines for you.
Spelling and characters
Run a spell check in the target language. Spell each name the same way every time. Netflix accepts only the characters in its glyph list.

Limits by language

Choose a language to see its limits. Each card comes from that language's own Netflix Timed Text Style Guide, and the card links to it. The cards show numbers for standard subtitles. They do not show grammar or punctuation rules, because a native speaker must check those.

English (USA)

Text

Characters per line
42
Maximum lines
2

Reading speed

Adult content
20 CPS
Children's content
17 CPS

Timing

Minimum duration
20 frames (0.83 s at 24 fps)
Maximum duration
7 seconds
Minimum gap
2 frames

Source: Netflix English (USA) Timed Text Style Guide, checked 2026.10.13.

The characters per line and the reading speeds come from each language's guide. The duration, gap, and line limits come from Netflix's general rules, unless a language guide says otherwise. The Japanese guide does, for the minimum duration. Many guides allow a higher reading speed for subtitles for the deaf and hard of hearing (SDH). Read the SDH part of the guide for those numbers.

Where the numbers differ

52 languages fall into a few groups. Most share one set of numbers. The groups below come from the same data as the cards.

Characters per lineAdult CPSChildren's CPSLanguages
421713Basque, Bulgarian, Catalan, Croatian, Czech, Danish, Dutch, Filipino, Finnish, French (Canada), French (France), Galician, German, Greek, Hebrew, Hungarian, Icelandic, Indonesian, Irish, Italian, Malay, Norwegian, Polish, Portuguese (Brazil), Portuguese (EMEA), Romanian, Russian, Sámi (Northern), Serbian, Slovak, Spanish (Latin America and Spain), Swedish, Ukrainian, Vietnamese, Welsh
422218Bangla, Hindi, Kannada, Malayalam, Marathi, Tamil, Telugu
422017Arabic, English (UK), English (USA)
421717Afrikaans, Zulu
1697Chinese (Simplified), Chinese (Traditional)
134No separate limitJapanese
16129Korean
351713Thai

Chinese, Japanese, and Korean have the lowest limits. Indian languages have the highest reading speeds, then English and Arabic. Netflix writes "up to" before each figure.

Timing rules for every language

Netflix writes its timing rules for 24 fps video. For other frame rates, "half a second" means more frames, but the minimum gap stays at 2 frames.

Rule24 fps30 fps60 fps
Half a second12 frames15 frames30 frames
Minimum gap2 frames2 frames2 frames
Minimum duration (5/6 second)20 frames25 frames50 frames

Netflix states the first two rows. The third row is our calculation from 5/6 second.

Gaps

Netflix wants a gap of either 2 frames or at least half a second. At 24 fps, it does not allow a gap of 3 to 11 frames. Close such a gap to 2 frames by moving the end of the first subtitle. Netflix says this is sometimes called "chaining".

Shot changes

  • If dialogue starts on a shot change, or up to half a second after it, start the subtitle on the first frame of the new shot.
  • If a subtitle ends within half a second before a shot change, extend it to the shot change, but stop 2 frames before it.
  • A subtitle may cross a shot change when the dialogue crosses it too.

Sync to the audio

Start a subtitle on the first frame of the audio. Netflix accepts 1 or 2 frames of difference. When no subtitle follows, the end time should ideally be at least half a second after the speech ends.

Check and fix with free tools

These tools run in your browser. They do not upload your file.

  • SRT validator finds broken timecodes, wrong order, bad characters, and problems with reading speed, lines, and timing in SRT and VTT files.
  • Subtitle fixer repairs overlaps, short and long subtitles, tight gaps, extra spaces, and empty subtitles. It shows each change before you download.
  • CPS calculator gives the reading speed of one subtitle.

The tools use Netflix's numbers. When your buyer's guide differs, follow the buyer's guide.

When your buyer is not Netflix

Every number on this page is Netflix's. YouTube, broadcasters, and other streaming services publish their own, and they can differ. Ask the buyer for the delivery specification before you start. Our subtitle formats guide covers the file side of delivery.

Netflix changes its guides over time, and each guide has a change log. Open the source link on a card to see the current numbers. The data here was checked on 2026.10.13.

Common questions

How many characters per line should a subtitle have?

In Netflix's guides, 42 is the limit for English and for most other languages. Thai is 35, Chinese and Korean are 16, and Japanese is 13. Other buyers may set different limits.

What is a good reading speed for subtitles?

Lower than the limit. Netflix allows up to 17 CPS for adult content in many languages, and 13 CPS for children's content. English allows 20 and 17. The Netflix Dutch guide calls its numbers upper limits and says to aim lower.

What does CPS mean in subtitles?

CPS means characters per second. Divide the number of characters in a subtitle by the seconds it shows. A subtitle of 34 characters that shows for 2 seconds reads at 17 CPS.

How long should a subtitle stay on screen?

Netflix sets a floor of 5/6 second and a ceiling of 7 seconds. It advises you to use the shortest time only for subtitles of one or two words, and to give longer text more time when you can.

What is the gap between subtitles?

The minimum is 2 frames, whatever the frame rate. Any longer gap should be at least half a second.

How many lines can a subtitle have?

Two at most, in every Netflix guide on this page. Netflix prefers one line when the text fits within the character limit.

How do you check subtitle quality?

Watch the whole file with the video at least once, because tools cannot judge sync or meaning. Then run a validator for timing, line, and reading-speed problems, and spell-check the text in the target language.

Does Netflix have a style guide for every language?

Netflix publishes a Timed Text Style Guide for 53 languages. This page lists 52. The Turkish guide gives no number for characters per line, so we left it out.

Catch QC problems while you edit

The editor has Netflix-style QC built in. Review and approve each language in one place.

Free forever plan. No card required. No sales call.

  • Every language gets a translator and a reviewer
  • Feedback on the exact line, not in an email thread
  • Only the approved version ships
  • See who's holding up which language
  • AI drafts in 82 languages, or bring your SRT
  • Private, in the browser, nothing to install

Sources