How to add captions to a screen recording on a Mac

The short answer

• Live Captions (System Settings → Accessibility → Live Captions) shows captions on screen as audio plays. It doesn't save them or add them to a video.
• By hand: type each line as a title in iMovie, or write an .srt subtitle file in TextEdit. Both work; both take a long time.
• Automatic and private: Shotnix transcribes your narration on the Mac, turns it into captions you can edit, burns them into the export, and saves matching .srt or WebVTT files. On macOS 15 and later it can translate them too, on your Mac.

Burned-in captions or a subtitle file?

Burned-in captions, also called open captions, are part of the picture. They show wherever the video plays, including feeds that autoplay muted and chat apps, but viewers can't turn them off or resize them.

A subtitle file, usually .srt or WebVTT (.vtt), travels next to the video. YouTube, Vimeo, and LinkedIn accept one as closed captions that viewers can switch on or off. For a video that goes to several places, make both.

What macOS gives you: Live Captions

Live Captions comes with macOS Ventura and later on Macs with Apple silicon. Turn it on in System Settings → Accessibility → Live Captions, and a floating window transcribes your Mac's audio or your microphone as it plays, processed on the Mac. Not every language or region is supported.

It's built for reading along, not for making captions. You can't save or export the text, and nothing is added to your recording. macOS 27 also adds automatic subtitles when you play a video that has none, in apps that use Apple's player such as Photos and Safari, starting with English. Those appear for whoever is watching on that Mac; they aren't written into the file.

Method 1: Type captions as titles in iMovie

1. Open your project in iMovie and click Titles above the browser.
2. Drag a simple lower-third style onto the timeline above the clip, where the first sentence starts.
3. Double-click the placeholder in the viewer and type the sentence.
4. Drag the title's edges in the timeline so it covers exactly that sentence.
5. Repeat for every sentence, then export with File → Share → File.

Note. iMovie can't generate captions, import an .srt, or export one. Every line is typed and timed by hand, and the result only exists as burned-in text.

Method 2: Write an .srt file by hand

An .srt file is plain text: numbered cues, each with a start time, an end time, and the words. Any platform that accepts subtitle files reads it.

1. Open TextEdit, create a document, and choose Format → Make Plain Text (⇧⌘T).
2. Play the recording in QuickTime Player and note when each sentence starts and ends.
3. Type the first cue: 1 on its own line, then the timing as 00:00:01,000 --> 00:00:04,200, then the words, then an empty line.
4. Repeat for every sentence, numbering the cues in order.
5. Save with a name ending in .srt (choose Use .srt if TextEdit asks) and Unicode (UTF-8) encoding, then upload it alongside the video.

Note. Budget several times the length of the video. Timing each line by ear is the slow part, and any later cut to the video shifts every time after it.

Method 3: Final Cut Pro, if you already own it

Apple's paid pro editor can transcribe English speech into captions on Apple silicon Macs, then export them as a subtitle file or burn them in. It's a big app to learn for captions alone, but a solid choice if it's already on your Mac.

Method 4: Automatic captions in Shotnix, made on your Mac

1. Record with the microphone on, or open any video with speech in the Shotnix editor.
2. Open the Captions tab, check the Language, and click Transcribe. Shotnix listens to the recording on your Mac and times every word.
3. At the top of the tab, switch from Edit by text to Captions. You get short, readable lines that follow your cuts, and with Highlight words on, each word lights up as it's spoken.
4. Fix names and product terms by editing any line in the list, and drag or trim caption chips on the timeline to adjust timing.
5. Choose a look (Classic, Bold outline, Minimal, or Highlight), a size (S, M, or L), and a position (top or bottom).
6. Need another language? On macOS 15 and later, click Translate under Languages and the captions are translated on your Mac.
7. Export the video with the captions burned in, and click Save Subtitles for an .srt or WebVTT file that matches the edited video.

Captions in Shotnix →

Why on-device matters

Caption services often work by uploading your audio to a server. That's a problem when a recording shows unreleased features, customer data, or internal tools. Shotnix doesn't upload anything: transcription uses Apple's on-device speech recognition, and the app has no account or cloud behind it.

On macOS 26 and later, Shotnix uses Apple's newer on-device speech model, downloaded once. On macOS 13 to 15 it uses the on-device dictation model for your language; if a language isn't available, turn on Dictation for it in System Settings → Keyboard, or pick another language. Chinese, Japanese, and Thai captions are spaced correctly.

Translation works the same way. On macOS 15 and later, Apple's on-device translation turns your captions into another language once that language is installed in System Settings, and nothing is uploaded.

The same transcript edits the video

Once a recording is transcribed, you can cut it by selecting words in the transcript and pressing Delete, remove filler words like um and uh in one click, and shorten long pauses. Captions and the .srt follow every cut, so you never re-time anything.

How to remove filler words from a video on Mac →

Tips for captions people can read

• Keep lines short: one or two lines on screen at a time, broken where you'd naturally pause.
• Proofread names, product terms, and numbers. That's where speech recognition slips most.
• Place captions away from the action. If your app's key controls sit at the bottom, move captions to the top.
• Cut before you caption by hand, since every edit shifts the timing. In Shotnix, captions follow your cuts either way.
• Mind accessibility rules. WCAG lists captions for prerecorded video with audio as a Level A requirement (success criterion 1.2.2).
• If transcription reports that speech recognition is off, turn Shotnix on in System Settings → Privacy & Security → Speech Recognition.

Questions