Free subtitle tools
Genuinely free utilities that run entirely in your browser. No signup, no upload, no watermark.
SRT and VTT carry the same subtitle cues in slightly different syntax. SRT uses commas before the milliseconds and is accepted by nearly every editor and player; VTT adds a WEBVTT header and is what HTML5 video players and most web platforms require. The converters below translate between the two instantly, entirely in your browser, so your file never leaves your machine.
The two checkers cover the other half of subtitle work: the character counter tests every caption line against the 42-character readability guideline broadcasters use, and the words-per-minute calculator tells you whether speech is too fast for comfortable captions. Use them forever; we make our living from transcription, not converters.
All 4 free subtitle tools
Universal subtitles into the web-native format, instant and client-side.
VTT → SRT ConverterWeb captions into the format editors and players accept everywhere.
Subtitle Character CounterCheck every caption line against the 42-character guideline.
Words Per Minute CalculatorMeasure speech pace from any transcript and recording length.
Subtitles and transcripts are not the same thing
A transcript is the words. A subtitle file is the words plus the exact moment each line appears and disappears, which is why the two are not interchangeable and why pasting a transcript into a video editor does not produce captions. Every cue in an SRT or VTT file carries a start time, an end time and one or two lines of text, and those timings are the part that takes the work.
That is also why line length matters more than it seems. A caption sits on screen for a couple of seconds, so a line that reads fine in a document becomes unreadable on a video. The 42-character guideline broadcasters use exists because it is roughly what someone can read in the time a cue is visible while also watching the picture. Going over is not an error exactly, but it is the difference between captions people follow and captions people switch off.
Speech pace is the other half of the same problem. Somewhere around 160 to 180 words a minute, comfortable captions stop being possible without either condensing what was said or letting lines flash past. The words-per-minute calculator exists to tell you which situation you are in before you start editing rather than after.
Which format do you actually need?
Use SRT unless something specifically asks for VTT. It is the format video editors, players and most platforms accept without argument, and it is the safer default when you are handing a file to someone else. YouTube, Premiere, DaVinci Resolve, CapCut and VLC all read it directly.
Use VTT when the video plays in a browser. HTML5 video expects it, most web players require it, and it supports positioning and styling that SRT does not. If you are embedding video on your own site, this is the one you want, and converting an SRT you already have takes a moment with the converter above.
Both formats come out of a transcription job on paid plans, timed from the word-level timestamps rather than guessed at. These utilities exist for the times you already have a subtitle file and need to convert, check or measure it, which is a different job and one that should not cost anything.
Frequently asked questions
Do these tools upload my subtitle file?
No. Conversion runs entirely in your browser with JavaScript. Nothing is sent to a server, which is also why the converters keep working if you lose connection after the page loads.
What is the difference between SRT and VTT?
They carry the same cues in slightly different syntax. SRT numbers each cue and uses commas before the milliseconds; VTT starts with a WEBVTT header, uses dots before the milliseconds, and supports styling. SRT is accepted by nearly every editor and player, while VTT is what HTML5 video players and most web platforms require.
Are these really free, with no catch?
Yes. There is no signup, no watermark and no usage cap. We make our living from transcription, not from converters, so these utilities stay free.
Starting from a recording instead of a subtitle file? Generate SRT/VTT from any audio or video or browse all transcription tools.