Free SRT caption generator

What an SRT file is

SRT (SubRip) is the most widely supported subtitle format. It is a plain text file made of numbered blocks: a start and end time in the form 00:00:01,250 --> 00:00:03,900, then one or two lines of text. YouTube Studio accepts it as a subtitle upload, and most video editors, including Premiere Pro and DaVinci Resolve, can import it. WebVTT (.vtt) is the web equivalent, used by HTML5 video players; this tool exports both.

How the timing is calculated

The text is split into captions at sentence ends, and at commas when a caption gets long, so a caption never cuts a sentence in an awkward place. Each caption then gets a share of the total duration in proportion to its words, with long words weighing more than short ones and a small pause after commas and full stops. The result follows natural speech far better than equal-length captions.

If you don’t know the exact duration, enter a pace instead: around 140 to 160 words per minute is typical narration. The default (147 wpm) matches the pace of Motiongist voices.

How to use the generator

Paste your script. Enter the duration in seconds, or switch to words per minute. Choose the maximum characters per line (42 is a common standard for subtitles, 32 suits big, bold social captions) and one or two lines per caption. Check the preview, where captions that would be hard to read in time are flagged, then download the .srt or .vtt file.

Nothing is uploaded: the file is built in your browser.

Caption tips

Keep reading speed comfortable: subtitle guidelines such as Netflix’s cap adult content at around 20 characters per second. Two short lines are easier to read than one long one. If your video has a voice-over generated with timestamps, use those for frame-accurate captions; this tool is for when you only have the text. Motiongist videos come with captions timed on the actual voice, plus an .srt to download.