SubToolbox

TXT to SRT Converter — Auto-Timed From Any Transcript

Turn a text transcript into a timed SRT file — reads inline timestamps if present, auto-times plain text, all in-browser.

Quick answer: Paste or upload your transcript: if lines carry timestamps such as [00:01:23] or 00:01:23–00:01:27 they become cue boundaries; otherwise the text is split into readable cues and timed automatically at your chosen reading speed — then download the SRT.

Drop a .txt transcript — or paste below. The file never leaves your device.

Pacing (used for lines without timestamps)
Core facts
ReadsPlain text, timestamped transcripts ([00:01:23], 00:01:23, a - b ranges)
TimingTimestamps honoured exactly; plain text estimated at 17 chars/sec default
TuningReading speed, min/max cue duration and gap are adjustable
OutputStandard SRT with sequential numbers
Honest noteAuto-timing is an estimate — always proof-watch before publishing

What this tool does

A text file has no timing information unless someone wrote it in. This converter handles both worlds. If your transcript carries inline timestamps — the [00:01:23] style that audio players and transcription tools print, or full 00:01:23–00:01:27 ranges — those become the cue boundaries, exactly. If it is plain prose, the tool splits it into sentence-sized cues, estimates each cue's duration from its character count at a reading speed you control (default 17 characters per second, within the 20/s comfort ceiling), and lays the cues back-to-back. You see the full cue table with durations before downloading, so an obviously wrong line never reaches your video.

Common uses

  • A meeting or interview transcript needs to become captions
  • A script typed in Notepad must be turned into an uploadable subtitle file
  • Podcast show notes with chapter timestamps become a caption draft
  • A transcription service delivered un-timed text

Why 17 characters per second

Subtitle guidelines for adult audiences hover around 20 characters per second as the maximum comfortable rate; 12–17 reads as unhurried. The default here is deliberately conservative — viewers complain about captions that vanish too soon far more often than about captions that linger. Raise the speed if your cues run long, lower the maximum duration if you need tight cuts.

Timestamped vs plain transcripts

If every paragraph of your file starts with a bracketed timestamp, the converter uses those boundaries verbatim and estimates only the missing end times. If there are no timestamps anywhere, everything is estimated. Mixed files work too: lines with timestamps anchor themselves, and untimed lines in between are fitted between neighbours.

Frequently Asked Questions

How does the converter time plain text?
It splits the text into sentence-sized chunks, then gives each chunk a duration of characters ÷ reading speed (default 17 chars/sec, adjustable from 8 to 25), clamped between your minimum and maximum cue durations. Cues run back-to-back with a small gap.
Which timestamp formats are recognised?
[00:01:23], 00:01:23, 1:23, [00:01:23 - 00:01:27], 00:01:23 --> 00:01:27, and the same with commas for milliseconds, at the start of a line. Text after the timestamp becomes the cue body.
Will the auto-timing match the actual audio?
No — and no tool can guess timing from text alone. It produces well-paced, readable captions that are correctly synchronised only if your text is a word-for-word transcript with real timestamps. For untimed text, treat the result as a draft to adjust against playback.
Can I fix individual cues after converting?
Yes — convert here first, then open the result in the cue viewer to fix individual timings and text, or re-run this converter with a different reading speed.

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