Batch subtitle converter
Convert a whole folder of subtitles at once
Drop SRT, WebVTT, ASS/SSA or MicroDVD files, choose the output format and download one zip. The conversion runs in this browser tab, so your files are never uploaded.
- $19 once, no subscription
- Free for 3 files per batch
- Files never leave your device
Drop files or a folder mixed formats are fine; each file is detected by its content.
Choose the output format and, if you need them, a time offset or tag stripping.
Download one file as is, or the whole batch as one zip with your folders kept.
- Reads
.srt.vtt.ass.ssa.sub- Writes
.srt.vtt.ass.sub.txt- Encodings
- UTF-8, UTF-16, Windows-1250, 1251 and 1252, Latin-1
Drop subtitle files or a folder here
.srt .vtt .ass .ssa .sub, any number of files
Options auto encoding, no offset, keep tags
Sample batch3 files
- lecture-03.vttReady
- interview-fr.assReady
- trailer-cut.subReady
1 00:00:00,500 --> 00:00:04,000 Welcome back. Today we look at colour grading. 2 00:00:04,200 --> 00:00:07,600 First, set the white balance on a neutral grey card. 3 00:00:07,800 --> 00:00:11,000 Then adjust <b>exposure</b> before saturation. 4
Converted in this tab. Nothing is uploaded.
Formats
Every common text subtitle format, both ways
Mix formats in one batch: each file is detected by its content, then written in the format you choose.
| From \ To | SRT | WebVTT | ASS/SSA | MicroDVD | Plain text |
|---|---|---|---|---|---|
| SRT | yes | yes | yes | yes | yes |
| WebVTT | yes | yes | yes | yes | yes |
| ASS/SSA | yes | yes | yes | yes | yes |
| MicroDVD | yes | yes | yes | yes | yes |
| Plain text | Output only: plain text has no timings to read | ||||
Carried across
Text, line breaks and timing. Italic, bold and underline in SRT, WebVTT and ASS; whole-line italics in MicroDVD.
Removed
Positions, colours, fonts, fades and karaoke timing; WebVTT NOTE, STYLE and REGION blocks; ASS comments and drawings.
Not supported
Image-based subtitles (VobSub .sub/.idx, Blu-ray .sup), burned-in captions, and speech-to-text. Plain text has no timings, so it is output only.
Privacy by design
Files never leave your device
Captionry is a page, not an upload service. The converter runs in your browser tab, the same way a desktop app runs on your computer.
The page loads the converter
One script from this site, about the size of a small image. Nothing loads from third parties.
Your browser reads the files
Files you drop are opened by this tab. No upload request is made, so unreleased and client material stays with you.
The zip is built in the tab
Converted files are packed into a zip in memory and saved with your browser’s normal download.
Check it yourself: load the page, turn off your network, and convert a batch. The only request the converter ever makes is a license-key check when you have unlocked Unlimited; it sends the key, never your files.
Options
The options a batch needs
Set them once; they apply to every file in the batch.
Whole folders
Drop a folder or a pile of files. Subfolders are kept inside the zip and files that are not subtitles are skipped.
Encoding detection
UTF-8, UTF-8 with BOM, UTF-16 and Windows-1252 are detected. Pick Windows-1250, 1251 or Latin-1 by hand. Output is always UTF-8.
Time offset
Move every cue earlier or later by a number of milliseconds, across the whole batch.
Strip formatting
Remove italic, bold and underline tags for platforms that want clean text. Position and colour codes are always removed.
Warnings per file
Malformed lines are skipped and listed under their file with line numbers, so one damaged file never stops the batch.
MicroDVD frame rates
Frame-based .sub files are read at the rate in their header line, or at the rate you choose, from 23.976 to 60 fps.
Pricing
Free for small batches, $19 once for the rest
No subscription and no account. The free tier is the full converter with a 3-file batch limit.
Free
$0per batch of 3 files
- Up to 3 files per batch
- Every format and option
- No sign-up
Unlimited
$19one-time
- Unlimited files per batch
- Every format and option
- License key to unlock your other browsers
- No subscription, no account
Not on sale yet: join the waitlist below. Full refund within 14 days of purchase: email support with your receipt.
Unlimited
Get an email when Unlimited can be bought
The free converter works now. Leave your email and we will write once, when the $19 unlock is available. No other mail.
FAQ
Questions
Are my files uploaded?
No. The page loads the converter into your browser tab, and the files you drop are read and converted there. They are never sent to us or anyone else.
Once the page has loaded you can disconnect from the internet and it still converts.
What does the free version do?
Everything, for up to 3 files per batch: every format, encoding detection, time offset and tag stripping. Unlimited removes the 3-file limit.
What do I get for $19?
Unlimited files per batch, paid once. After payment you come back to Captionry, which confirms the payment and shows your license key. The browser you buy in is unlocked at once; enter the key to unlock your other browsers, or again after clearing site data.
Which formats are supported?
Input: SRT (.srt), WebVTT (.vtt), ASS and SSA (.ass, .ssa) and frame-based MicroDVD (.sub). Output: the same four plus plain text (.txt) without timings.
Image-based subtitles (VobSub .sub/.idx, Blu-ray .sup) are not text and cannot be converted.
What happens to styling?
Italic, bold and underline carry across every format except plain text; MicroDVD keeps whole-line italics only. Positions, colours, fonts and karaoke timing are removed, because most formats cannot carry them.
What if a file is damaged?
Lines that cannot be read are skipped, and the file shows a warning with the line numbers. The rest of the batch converts normally.
Can I get a refund?
Full refund within 14 days of purchase: email support with your receipt.
Single conversions
Converting one pair of formats?
Convert the next batch in one go
Free for 3 files at a time. $19 once for unlimited batches, no subscription.