Why Merges Fail: 10 Common Causes

If a merge fails, it is usually one of these issues. Use this checklist to debug quickly.

1) Unsupported codec

• Fix: Use Copy mode or switch to H.264/AAC.

2) Incompatible container

• Fix: Try MP4 for compatibility or MKV for flexibility.

3) Corrupted input file

• Fix: Re-export the media or test with another file.

4) Subtitle encoding problems

• Fix: Save subtitles as UTF-8.

5) Memory limits

• Fix: Close tabs, use smaller files, or use Copy.

6) Very large files

• Fix: Split files or test with a short clip first.

7) Mismatched frame rates

• Fix: Re-encode video to a standard frame rate (e.g., 30).

8) Audio track issues

• Fix: Re-encode audio to AAC.

9) Browser limitations

• Fix: Use desktop Chrome/Edge/Firefox.

10) Unsupported subtitle type

• Fix: Convert to SRT or VTT.