Hi,

Below we have mentioned the fix guide for CapCut Auto Captions stuck at 45% on macOS (especially on v4.0.0).
This issue has become very common after the 4.0.0 update and is not caused by your device. It is usually due to a bug in CapCut’s speech recognition engine, temporary server issues, or corrupted cache.

Below is a step-by-step plan, which you can adopt in your case.

1. First: Confirm the issue isn’t Video/Audio related

Auto captions get stuck at ~45% specifically when CapCut parses the audio waveform, so check:

Audio format is supported

MP4, MOV, AAC, MP3 are safe.

No extremely long or corrupted audio

If your video is 30+ minutes, split the timeline and generate captions only for the segment.

2. Delete only the Speech-to-Text cache (the most effective fix)

This is not the same as deleting the whole CapCut cache.

Steps:

1. Quit CapCut completely.

2. Go to Finder → press Cmd + Shift + G.

3. Paste this path:

   ~/Library/Application Support/CapCut/User Data/


4. Delete these folders only if they exist:

   • STT

   • temp

   • Cache (optional but recommended)

5. Reopen CapCut → Try generating subtitles again.

This alone fixes the problem for most of the people who have reported this issue on our forum.

3. Turn off “Hardware Acceleration”

This bug is linked to M1/M2/M3 GPU decoding.

Steps:

CapCut → Preferences → Performance → Hardware Acceleration → OFF

Restart CapCut.

Try subtitle generation again.

4. Change language to “English (United States)” temporarily

CapCut’s engine sometimes fails if the selected language is missing backend files.

Try:

1. Auto Caption → Language → English (US)

2. Generate captions

3. After success, switch back to your language

This is a known workaround.

5. Export Audio → Reimport → Generate Captions on audio file only

Sometimes CapCut fails when recognizing audio from the full video.

Steps:

1. Right-click your video → Detach Audio

2. Export audio only (File → Export Audio)

3. Start a fresh project

4. Import ONLY the audio file

5. Generate captions

If it works, import into your main project.

6. Update CapCut and MacOS

CapCut older version had a confirmed STT bug.
Check:

CapCut → Menu → Check for Updates

Or download latest .dmg manually.

7. Log out & back in (SSO token bug)

CapCut’s speech-to-text uses online servers. If your login token is corrupt, captions freeze at ~40–50%.

Steps:

1. Log out of CapCut

2. Quit the app

3. Log in again (use the same SSO you normally use)

8. Complete reinstall (without losing your projects)

Only do this if nothing else works.

IMPORTANT

Before uninstalling:

Go to:

Copy the folder somewhere safe — this contains your local project files.

After reinstalling CapCut, paste it back into the same directory.

If nothing mentioned above works then:

Use CapCut Web Captions (same engine, different server):

https://www.capcut.com/editor?scene=caption

Upload video → Auto captions → Export → Re-import into CapCut for editing.

This bypasses the macOS bug entirely.