How to Create an SRT File on Mac (2026)

An SRT file is a plain text file with a specific structure: a number, a timecode line, the caption text, then a blank line. You can write one in TextEdit in two minutes, generate one automatically from your audio in about the same time, or export one from any video editor. The only thing that trips people up is TextEdit's default rich-text mode, which silently produces a file that no player will read.

All three methods below, plus the format rules that make the difference between a working file and a broken one.

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What an SRT File Actually Is

SubRip Subtitle — .srt — is the most widely supported subtitle format in existence. YouTube, Vimeo, LinkedIn, Facebook, Premiere, Final Cut, VLC, QuickTime (via conversion) and every broadcast system reads it.

The structure, exactly:

1
00:00:01,000 --> 00:00:04,120
This is the first caption.

2
00:00:04,400 --> 00:00:07,000
This is the second one, and it
can run to two lines.

Four rules, and all four matter:

1. A sequential number on its own line, starting at 1.
2. A timecode line in HH:MM:SS,mmm --> HH:MM:SS,mmm format. Note the comma before the milliseconds, not a period. This is the single most common mistake.
3. The caption text, one or two lines. Three is technically allowed and practically unreadable.
4. A blank line between every block. The last block should end with a newline.

Get any of those wrong and most players reject the entire file rather than the one bad block.

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Method 1: Write It by Hand in TextEdit

Fine for a short video or for fixing a few lines. Painful past about twenty captions.

1. Open TextEdit.
2. Format → Make Plain Text (Shift+Cmd+T). This step is not optional. TextEdit defaults to Rich Text Format, and an .srt saved as RTF contains formatting bytes that break every parser.
3. Type your caption blocks in the structure above.
4. File → Save.
5. Name it yourvideo.srt — with the .srt extension, not .txt.
6. In the save dialog, set Plain Text Encoding to Unicode (UTF-8).
7. macOS will ask whether to use .srt or append .txt. Choose Use .srt.

Getting the timecodes: open the video in QuickTime, step through with the arrow keys, and read the time. Tedious but accurate. For anything longer than a minute, use method 2.

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Method 2: Generate It Automatically from Audio

The practical option for anything real. A transcription tool listens to the audio, produces the text, and timestamps it.

With BlitzCut: import the video, let it transcribe, then export captions as .srt. Because it transcribes for captioning anyway, the SRT comes out of work you were already doing. Native Mac app.

With MacWhisper: a Mac front-end for Whisper speech recognition. Runs locally, no upload, free tier available, exports SRT and VTT directly. Good choice if the audio is sensitive or you're offline.

With Descript: transcribes on import, exports SRT under Export → Subtitles. Heavier tool, strong if you're also editing.

With YouTube: upload the video as unlisted, wait for auto-captions to generate, then download the .sbv from Studio and convert. Free, slow, and the round trip is a hassle — but it costs nothing.

Accuracy note: every automatic method needs a proofread. Names, brand terms, and technical vocabulary are what they get wrong, and those are usually the words that matter most. Budget a few minutes to fix them — see how to edit an SRT file.

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Method 3: Export from a Video Editor

If the captions already exist on your timeline:

Final Cut Pro: add captions to the timeline (Edit → Captions → Add Caption, or paste a transcript), then File → Export XML won't do it — use File → Export Captions, choose SRT, and pick the caption role.

Premiere Pro: with captions in the sequence, File → Export → Captions, or in the Export panel enable Captions and set the format to SubRip SRT (.srt) with "Create Sidecar File" selected.

DaVinci Resolve: in the Deliver page, open the Subtitle Settings tab, enable Export Subtitle, and choose As a separate file → SRT.

CapCut (Mac): export captions from the text panel — support varies by version, and it's less reliable than the others. Often faster to generate the SRT separately.

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The Rules That Make Captions Readable

A technically valid SRT can still be a bad subtitle file.

Characters per line: 32–42. Past that, viewers can't read a line in the time it's on screen.

Lines per caption: two maximum.

Duration: minimum 1 second, maximum about 7. Under a second is unreadable; over seven means you should have split it.

Reading speed: roughly 15–20 characters per second. If a caption is 60 characters, it needs at least 3 seconds.

Gaps: leave at least 2 frames (~80ms) between consecutive captions so the eye registers a change.

Break lines at natural points: after punctuation or before a conjunction, not mid-phrase. I went to the shop and\nbought milk reads worse than I went to the shop\nand bought milk.

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Checking the File Works

Before you rely on it:

1. Open it in VLC alongside the video (Subtitle → Add Subtitle File). VLC is forgiving, so if VLC won't read it, nothing will.
2. Check the encoding. If accented characters show as é or �, the file was saved as something other than UTF-8. Re-save it.
3. Check the first and last caption against the video. An offset at the start usually means the whole file is shifted.
4. Upload it somewhere strict. YouTube's caption upload rejects malformed files with a specific error, which is a useful validator.

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Frequently Asked Questions

Can I make an SRT file in TextEdit?

Yes, but you must switch to plain text first with Format → Make Plain Text (Shift+Cmd+T), save with UTF-8 encoding, and use the .srt extension. An SRT saved as rich text will not work in any player.

What's the difference between a comma and a period in SRT timecodes?

SRT requires a comma before the milliseconds — 00:00:01,000. A period is WebVTT syntax. Using the wrong one is the most common reason a file fails to load.

Do I need special software to create an SRT file?

No. It's plain text, so any plain-text editor works. Software helps by generating the timecodes automatically, which is the genuinely tedious part.

How do I create an SRT file from a video automatically on Mac?

Use a transcription tool that exports SRT — BlitzCut, MacWhisper, or Descript. All three transcribe the audio and timestamp it, then export a sidecar .srt file.

What encoding should an SRT file use?

UTF-8. Anything else breaks accented and non-Latin characters, and some players will refuse the file entirely.

Can QuickTime play SRT files?

Not directly — QuickTime Player has no "add subtitle file" option for SRT. Use VLC for playback with an external SRT, or burn the subtitles into the video. See how to burn subtitles into video on Mac.

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Skip the timecodes entirely. BlitzCut AI transcribes your video on your Mac, lets you fix any word in the text, and exports a clean UTF-8 SRT — or burns styled captions straight into the file.

Try BlitzCut AI free for 3 days

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Related: How to Edit an SRT File · SRT vs VTT vs SBV · How to Burn Subtitles into Video on Mac · Add Subtitles to Video on Mac Automatically · Best Subtitle Generator for Mac

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Last Updated: August 23, 2026 Category: Subtitles & File Formats Topic: Creating SRT Files on Mac