SRT editor
Open an .srt or .vtt and fix it row by row: the words, the start and end times, captions to split or merge. Overlaps and captions too fast to read are flagged as you go.
- Free, no sign-up
- Your file never leaves your browser
- Overlaps and reading speed checked
What the editor checks
- Times
- 00:01:02,345A comma or a period both read; exports write each format's own
- Overlaps
- FlaggedA caption that starts before the previous one ends
- Reading speed
- 20 characters a secondNetflix, English, adult programs
- Line length
- 42 charactersNetflix, English
Editing, splitting and merging
Each caption is a row: its number, start, end, length on screen, reading speed and text. Type a time with a comma or a period, as 00:01:02,345 or 1:02.345; it is rewritten in full when you leave the box. Split breaks a caption at the cursor and divides its time in proportion to the characters on each side; Merge joins it with the next caption. Undo steps back through the last 60 changes. Export numbers the captions 1, 2, 3 in order and writes SubRip or WebVTT, with any caption that still has an unreadable time or no text left out and counted.
Your draft stays in this browser
The editor keeps your work in this browser's local storage so a closed tab doesn't lose it. Nothing is uploaded, and Clear removes the draft. For Netflix, BBC or DCMP limits side by side, check the exported file in the caption checker; to move every caption at once, use the subtitle time shifter.
Sources: Library of Congress: SubRip Subtitle format (SRT) · W3C: WebVTT, the Web Video Text Tracks Format (Candidate Recommendation Draft, May 20, 2026) · Netflix English (USA) Timed Text Style Guide, read on October 28, 2026.
Embed this editor
Teachers, bloggers and course creators can put this SRT editor on their own page for free. Paste the code below into your page's HTML. It loads from markstudios.com, so it stays current when we update the numbers.
Questions, answered.
Anything else? Message Mark and you'll get a written reply within one business day.
How do I edit an SRT file online?
Open the .srt (or paste it) and each caption becomes a row with its start time, end time and text. Change any of them, split or merge captions, then download an .srt or a .vtt. It all happens in your browser; nothing is uploaded.
How do I fix overlapping subtitles?
Rows that start before the previous caption ends are flagged. Move that caption’s start after the previous end, or end the previous caption earlier, or merge the two if they belong together. “Sort by time” puts captions that are out of order back in sequence.
How do I split or merge captions?
Click in the text where you want the break and press Split: the time is divided in proportion to the characters on each side. Without a cursor, Split breaks at the line break or the space nearest the middle. Merge joins a caption with the next one and keeps both their times.
How fast should captions be?
Netflix’s English style guide allows up to 20 characters a second for adult programs and 42 characters a line, and the editor flags rows over either. For BBC or DCMP limits and children’s speeds, run the file through the caption checker.
Is my work saved?
Your draft is kept in this browser’s local storage, so it is still here if you close the tab, and nothing is sent anywhere. Clear removes it.
Can I edit VTT files too?
Yes. Open a .vtt and export a .vtt or an .srt. The editor keeps text, times and the top-of-frame position; WebVTT extras SubRip can’t hold, such as NOTE and STYLE blocks and voice tags, aren’t kept.
Rather not edit captions line by line?
Mark can add captions to your videos, burned in or as SRT files, priced in the instant quote, and you work directly with Mark.
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