Free browser tool
SRT and VTT Caption File Maker
Paste a transcript or an existing caption file, fix the timing, and download .srt or .vtt. Everything runs in your browser.
Free · Runs in your browser · No sign-upNothing is uploaded. Your files and text stay on this device.
Plain text: it will be timed at 2.5 words per second. A line that starts with a time (0:05 …) starts at that time.
Captions: 5 · Length: 0:16.8
| Start | End | Caption | |
|---|---|---|---|
Show the file
1 00:00:00,000 --> 00:00:02,000 Welcome back to the channel. 2 00:00:02,000 --> 00:00:06,400 Today we are making a caption file without any special software. 3 00:00:06,400 --> 00:00:10,400 Paste your own transcript here, choose a reading speed, and 4 00:00:10,400 --> 00:00:11,600 press Make captions. 5 00:00:11,600 --> 00:00:16,800 You can fix any line in the table before you download the file.
Want the clips made automatically?
ClipX finds the best moments in a long video, cuts them to 9:16, follows faces and adds captions. One video a day is free, up to 3 hours long. Pro is $4.99 for the first month, then $20/month.
Most video platforms take captions as a small text file: SRT for YouTube, Facebook and most editors, WebVTT for web players and many course platforms. This tool writes both. Paste plain text and it splits the words into short captions and times them at a reading speed you choose. Paste an SRT or VTT file and it reads the cues as they are, so you can convert, shift or clean them.
Nothing is sent to a server. The text stays in this browser tab, and the download is made on your device.
How it works
Paste or open your text
Paste a transcript, or open a .txt, .srt or .vtt file. The tool tells you which kind it found.
Set the timing
Pick a reading speed and a line length, then press Make captions. If the audio starts late, shift every caption by a few seconds.
Check and download
Fix any caption in the table, then download the .srt or .vtt file and upload it with your video.
What you get
- SRT and WebVTT files from the same captions
- At most two lines per caption, split at a natural point
- Reading speed from 1.5 to 4 words per second
- A timing shift for captions that start too early or too late
- Overlapping captions fixed on download, so players show one at a time
SRT or VTT: which file do you need?
SRT (SubRip) is the older and more common format. Each caption has a number, a start and end time with a comma before the milliseconds, and one or two lines of text. YouTube, Facebook, LinkedIn, Premiere Pro, DaVinci Resolve and most other editors read it.
WebVTT starts with the word WEBVTT, uses a full stop before the milliseconds and does not need the numbers. HTML5 video players read it, and course and video hosting platforms often ask for it. The caption text is the same in both; only the wrapping differs, which is why converting is safe.
How the timing is worked out
For plain text, the tool counts the words in each caption and shows it for that many words divided by your reading speed, with one second as the shortest caption. About 2.5 words per second suits most talking videos. Fast speakers need a higher number, slow tutorials a lower one.
These times are an estimate, not a match to your audio. For a short clip they are often close enough after a shift. For a long recording, put times at the start of some lines (0:00, 1:15, 3:40) and the tool keeps each part inside its own window.
When you want captions made for you
Typing a transcript and checking times is slow for every clip. ClipX transcribes the video itself, finds the strongest moments, cuts them into vertical clips and adds word-by-word captions you can restyle in the editor. One video a day is free to process, edit and preview.
Frequently asked questions
Is this caption maker free?
Yes. The tool is free, needs no account and has no limit on how many files you make. It runs in your browser, so your text is never uploaded.
Can I convert SRT to VTT, or VTT to SRT?
Yes. Paste or open either file, press Make captions, then download the other format. The caption text and times stay the same.
Will the captions line up with my audio?
Plain text is timed by reading speed, so it is an estimate. Use the shift control if everything is early or late, add times at the start of lines for long videos, and edit single captions in the table.
How do I add an SRT file to YouTube?
In YouTube Studio, open the video, go to Subtitles, pick the language, choose Add, then Upload file and select With timing. Pick the .srt file you downloaded here.
How long should one caption be?
Keep a caption to two lines of about 32 to 42 characters each, shown for at least one second. Shorter lines read better on phones, which is why 32 characters is a good choice for vertical video.
Related guides
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