Subtitle Line Length Limiter

How it works

1. Paste your SRT or VTT subtitle file into the input area, or drop a file directly onto it.
2. Pick a character-per-line limit from the presets, or enter a custom value between 20 and 80.
3. Decide whether you want overly long cues split into two cues with proportional timing — on by default.
4. The reformatted output appears instantly in the right panel as you adjust settings.
5. Copy the result to your clipboard or download it as a fresh SRT or VTT file ready for your video editor or streaming platform.

Before and after example

Here is a single overlong line reformatted to the 42-character Netflix limit. Because the wrapped text needs more than two lines, the tool splits it into two cues and divides the original duration proportionally by character count.

1
00:00:01,000 --> 00:00:05,000
This is a really long single line of subtitle text that clearly runs well past the forty-two character limit and needs wrapping.

1
00:00:01,000 --> 00:00:03,438
This is a really long single line of
subtitle text that clearly runs well past

2
00:00:03,438 --> 00:00:05,000
the forty-two character limit and needs
wrapping.

Choosing the right character limit

32 characters — broadcast tight

Used by some traditional broadcasters and live captioning workflows where on-screen real estate is limited or text must stay readable on small displays. Tight limits force frequent line breaks and are rarely needed for modern streaming work.

37 characters — BBC standard

The BBC subtitle guidelines specify 37 characters per line as the working maximum for pre-recorded content. This is widely adopted across UK broadcast captioning and many European public service broadcasters.

42 characters — Netflix standard

Netflix's published Timed Text Style Guide specifies 42 characters per line as the maximum for most languages. This has effectively become the de facto standard for streaming submissions and is the most common limit used by professional captioners worldwide.

47 characters — loose web

A looser limit suited to web video players with larger viewport allocations, internal company training videos, or YouTube uploads where strict style compliance isn't required. Gives more flexibility but can produce subtitles that overrun mobile screens.

Common use cases

Fixing YouTube auto-caption line lengths

YouTube's automatic captions and Whisper-style AI transcription tools produce subtitles with no awareness of professional line length conventions. A 30-second clip can come back with one long unbroken line that overruns the screen on any device. Running the output through this tool reformats everything to a readable limit in a single pass.

Preparing subtitles for Netflix or streaming submission

Streaming platforms reject subtitle files that exceed their style guide specifications. Netflix in particular is strict about the 42-character limit and will return files for resubmission if they don't comply. Catching the violations before submission saves a round-trip and gets your captions accepted on the first pass.

Cleaning up subtitles from machine translation

Machine-translated subtitles often expand text significantly compared to the source language — German and Finnish translations can be 30 percent longer than English. The original line breaks no longer fit. Re-wrapping after translation restores professional formatting without manual line-by-line editing.

Who uses this tool

• Streaming and broadcast captioners preparing files to Netflix (42), BBC (37), or platform-specific limits before submission.
• YouTubers and video editors cleaning up auto-generated captions that arrive as long, unbroken lines.
• Translators and localizers re-wrapping subtitles after translation expands the text beyond the original line breaks.
• E-learning and corporate video teams standardizing caption formatting across large content libraries.
• Anyone working from Whisper or AI transcripts that ignore professional line-length conventions.

Why use this tool

Deterministic line wrapping means the same input always produces the same output — unlike AI tools that may decide to "improve" your dialogue text while they reformat. When a cue must be split, proportional timing is calculated from character counts in plain JavaScript, so timestamps stay exact across thousands of cues; large language models often hallucinate sequential floating-point math on long files. Everything runs in your browser: no upload, no server, and no account, so your subtitles never leave your device. There are no token or context limits either — a three-hour film re-wraps in milliseconds on a typical laptop. Toggle presets and splitting on or off and watch the output update live before you copy or download. It pairs naturally with the rest of SubtitlesEdit: strip tags first, fix line lengths here, then adjust timing or fix overlaps when cues drift on the timeline.

Frequently Asked Questions

What character limit should I use?

For streaming platforms, 42 (Netflix's standard) is the safest default. For UK broadcast or BBC-style work, use 37. For loose web video or internal training content, 47 is fine. If you're producing for a specific platform, check their style guide for the exact requirement and use the custom field.

What happens to the timing when a cue is split in two?

The tool splits the timing proportionally based on character count. If the first half of the wrapped text is 60 percent of the total characters, it gets 60 percent of the original cue's duration, and the second half gets the remaining 40 percent. Original timestamps are preserved at the boundaries — the first cue starts when the original did, and the second cue ends when the original did.

Why didn't the tool break this long word across two lines?

By design. Breaking a word mid-character produces unreadable results and breaks language conventions. If a single word exceeds your character limit (typically a long URL or unusual compound word), the tool allows that line to overflow rather than fragment the word. You can manually edit the cue or raise the character limit if needed.

Will this work on subtitles in non-Latin scripts (Chinese, Arabic, etc.)?

Partially. The character-counting logic treats each character as one unit, which works correctly for Chinese and Japanese where each character is roughly one display unit. For Arabic and Hebrew, the right-to-left direction is preserved but you should verify the wrap points make sense for your language. The 42-character convention is Latin-script-centric; consider lower limits (15–20) for CJK scripts.

What if a split cue still exceeds two lines after splitting?

The tool splits each oversized cue once. If one of the resulting halves is still too long for two lines at your character limit, the tool accepts the overflow rather than recursively splitting (which would fragment timing absurdly). This is rare — it only happens with extremely long cues at very tight limits. The fix is to raise your character limit or manually break the cue further.

Is anything uploaded to your server?

No. Everything happens inside your browser — your subtitle file never leaves your device. There's no upload, no account, and no tracking of file contents. You can verify by disconnecting from the internet after loading the page; the tool will continue to work normally.

Does the tool merge short lines or only break long ones?

Both. It re-flows the full text of each cue to fit your character limit, so a long line is broken across multiple lines and two short lines that comfortably fit together are merged into one. The result is consistent wrapping throughout the file rather than a mix of your original line breaks and new ones.

Can I limit line length without creating extra cues?

Yes. Untick the "Split overly long cues" checkbox in Settings. With splitting off, every cue keeps its original timing and stays a single cue — the text is simply wrapped to your chosen limit, even if that leaves more than two lines on screen. Turn splitting back on when a platform requires strict two-line cues.

Why are the subtitle numbers different in my SRT output?

The tool renumbers SRT cues sequentially from 1 in the output. If your input had gaps in its numbering, or a cue was split into two, the output numbers won't match the originals. This is expected and keeps the file valid — players rely on cue order and timing, not on the specific index values.

Why does my VTT file have extra blank lines between cues?

The VTT output can include an extra blank line between cues. This is harmless: the WebVTT format treats any run of blank lines as a single separator, so the file plays correctly in every compliant player and editor. If you prefer tighter spacing, collapse the blank lines in any text editor.

How does this fit with other subtitle tools?

It is one step in a clean-up workflow. Strip styling with the Subtitle Tag Stripper, fix line lengths here, then correct timing with the Subtitle Time Shifter or resolve clashes with the Subtitle Overlap Fixer. If you need to break a long file into smaller parts rather than re-wrap lines, use the Subtitle Splitter instead.

Related tools

• Subtitle Tag Stripper — remove HTML, styling, and formatting tags before re-wrapping.
• Subtitle Time Shifter — move every cue earlier or later by a fixed offset.
• Subtitle Overlap Fixer — resolve cues whose timings collide on the timeline.
• Subtitle Merger — join multiple subtitle files into one.
• Subtitle Splitter — break one subtitle file into smaller parts.