The fastest way to add subtitles in iMovie

iMovie has a built-in captions feature that works in two ways: you can add text manually, or let iMovie generate captions automatically from your video's audio. The automatic route is faster if your audio is clear, but manual captions give you complete control over timing and wording.

To add captions automatically, select your video clip in the timeline, click the Captions button (the speech bubble icon) in the toolbar, then choose "Auto Captions". iMovie will analyze the audio and create a caption file. You can then edit individual captions by double-clicking them on the timeline.

To add captions manually, click the Captions button and select "Add Caption". A text box appears on your timeline—type your text, then drag the edges of the caption box to set when it appears and disappears. You can add as many manual captions as your project needs.

Key Takeaways

  • iMovie's Auto Captions feature analyzes your audio and generates captions automatically, which saves time if your dialogue is clear and your microphone quality is good.
  • Manual captions let you type text directly into the timeline and control exactly when each caption appears and disappears.
  • You can edit, delete, or reposition captions after they are created by double-clicking them or dragging their edges on the timeline.
  • Captions appear as white text on a black background by default, but you can change the font, size, and color in the caption formatting panel.
  • Export your finished video with captions included by going to File > Share and choosing your output format—captions are embedded in the file.

When to use Auto Captions versus manual captions

Auto Captions work best when your audio is clean: no background noise, no overlapping voices, and clear speech. If you recorded in a quiet room with a decent microphone, Auto Captions will likely catch most of what was said. If your audio has music, traffic, or multiple people talking at once, the automatic transcription will miss words or misidentify them.

Manual captions are the right choice if your audio is noisy, if you want to add text that is not spoken (like on-screen graphics or translations), or if you need captions in a language other than what was recorded. Manual captions also let you add emphasis, break long sentences into readable chunks, or simplify technical language for your audience.

Many editors use both: run Auto Captions first to get a rough transcript, then go through and fix errors, adjust timing, and add any missing context. This hybrid approach is faster than typing everything from scratch.

Editing and formatting captions after you create them

Once a caption exists on your timeline, you can change what it says, when it appears, and how it looks. Double-click any caption to open the text editor and type new words or fix mistakes. The caption will update when ready on your video preview.

To change when a caption appears, click and drag the left or right edge of the caption box on the timeline. Drag the left edge to move the start time, or the right edge to move the end time. You can also drag the entire caption box left or right to shift both the start and end times together.

To change the font, size, color, or background of your captions, select a caption and look for the formatting options in the inspector panel on the right side of the screen. iMovie offers several preset styles (white text on black, black text on white, and others), or you can customize the appearance yourself. Changes you make to one caption do not affect others unless you save your changes as a new style.

Fixing Auto Captions that got words wrong

Auto Captions sometimes misidentify words, especially names, technical terms, or accented speech. The good news is that fixing them is straightforward: double-click the caption that needs correction, type the right word, and press Enter. iMovie does not re-analyze the audio when you edit—it just changes the text.

If Auto Captions missed entire phrases or created captions that do not match what was actually said, you have two options. You can edit each caption individually, or you can delete the Auto Captions and add manual captions instead. To delete Auto Captions, select them on the timeline and press Delete, then add new manual captions as needed.

Keep in mind that Auto Captions work best with English-language audio. If your video is in another language, manual captions or a third-party transcription service may give you better results.

Positioning captions so they do not cover important parts of your video

By default, iMovie places captions at the bottom of your video. If your video has important action or text at the bottom of the frame, captions will cover it. You can move captions to a different position by selecting a caption and dragging it anywhere on the screen.

Click once on a caption to select it, then drag it to a new location. You can place captions at the top, middle, or sides of your frame. If you want all your captions in the same position, move them one at a time, or select multiple captions at once (hold Shift and click each one) and then drag them together.

Some editors add a semi-transparent background behind captions to make them readable over busy video. In the formatting panel, you can adjust the background opacity or choose a solid color background that contrasts with your video.

Exporting your video with captions included

When you export your finished video from iMovie, captions are included automatically. Go to File > Share, then choose your export format (File, YouTube, Vimeo, or another option). The captions you created will be embedded in the exported video file.

If you are uploading to YouTube or Vimeo, the captions will appear in the video player and viewers can turn them on or off. If you are exporting as a standalone file (like an MP4), the captions are burned into the video itself—they cannot be turned off by the viewer, but they will play on any device that can play the video.

Before you export, play through your video one more time to check that captions are readable, timed correctly, and do not cover important visuals. Small timing issues or typos are much harder to fix after export.

Frequently Asked Questions

Can I add captions in a language other than English?

Auto Captions only works with English audio. For other languages, you will need to add manual captions by typing the text yourself. Some editors use third-party transcription services (like Rev or Descript) to generate captions in other languages, then import them into iMovie.

What if my captions are out of sync with the audio?

Select the caption on the timeline and drag its edges to adjust the start and end times. If many captions are out of sync, delete the Auto Captions and try again—sometimes re-running Auto Captions with adjusted audio levels gives better results. You can also slow down or speed up your audio track to match the captions.

Can I export just the caption file without the video?

iMovie does not export captions as a separate file. Captions are embedded in the video when you export. If you need a separate caption file (like an SRT or VTT file), you would need to use a different video editor or a dedicated captioning tool.

How do I make captions bigger so they are easier to read?

Select a caption and look for the font size option in the formatting panel on the right. You can increase the size there. If you want all captions to be larger, change the size on one caption, then select all captions and explore the same size to the whole project.

Do captions slow down my computer when I am editing?

No. Captions are lightweight and do not significantly impact editing performance. iMovie handles them smoothly even on older Macs. The Auto Captions feature does use processing power while it is analyzing audio, but once captions are created, they do not slow down your editing.