Something not working in the subtitle generator? Whether you use the free AI subtitle generator, the auto subtitle generator for video or the YouTube subtitle generator, find your problem below and follow the steps.
Files
My file is not accepted or cannot be read
The tool needs audio that your browser can decode.
Check the extension: MP4, MOV, WebM, MKV, MP3, WAV, M4A, AAC, OGG or FLAC.
Convert unusual formats (AVI, WMV, old codecs) to MP4 or MP3 with a free converter such as HandBrake or VLC.
Make sure the file plays normally in your browser or media player first.
Confirm the file actually contains an audio track.
Download
The AI model will not download
The model is fetched once from a public model host.
Check your internet connection and try again.
Turn off VPNs, ad blockers or privacy extensions that block downloads from other websites, then reload.
Make sure you have a few hundred MB of free browser storage.
Try Fast quality first, since its model is the smallest.
Speed
It is very slow
Speech recognition is demanding, and speed depends on your hardware.
Choose Fast quality for drafts.
Close other tabs and heavy applications.
Plug in a laptop and keep the tab visible; browsers slow down background tabs.
Split very long recordings into parts.
Memory
I see an out-of-memory error
Large files and large models need a lot of RAM.
Switch to Fast quality.
Use a shorter file or split it into sections.
Close other tabs and restart the browser.
Export audio only (MP3) from a very large video and use that instead.
Accuracy
The subtitles are wrong or missing words
Accuracy depends on audio quality and language.
Select the spoken language manually instead of auto-detect.
Try Balanced or High accuracy.
Reduce background music and noise before processing if you can.
Correct the remaining mistakes in the editor.
Language
It detected the wrong language or mixed languages
Short clips and mixed speech can confuse detection.
Choose the main spoken language from the list.
For a clip in two languages, process each section separately.
To get English text from other languages, choose “Translate speech to English”.
Display
Special characters look broken in my video player
This is usually an encoding or font issue in the player.
Our files are UTF-8. In the player, set the subtitle encoding to UTF-8.
Try the VTT file instead of SRT.
Choose a font that supports your language in the player settings.
Browser
Nothing happens or the page shows an error
Modern browser features are required.
Update Chrome, Edge, Firefox or Safari to the latest version.
Disable extensions that block scripts and reload the page.
Try a private window to rule out stored data problems.
Clear this site’s data in your browser settings to remove a corrupt model download.
Sync
Subtitles appear too early or too late
Timing comes from the audio of the file you upload.
Use the same file in your editor that you used in the generator; any cut or trim changes timing.
If you trimmed the start later, shift all subtitles in your editor by the same amount.
Check that the video frame rate and the player are not out of sync with the audio.
Regenerate subtitles from the final edit.
Preview
The video preview is black or will not play
Your browser may not be able to play that video codec, even if it can read the audio.
Audio-only files show a black preview by design.
Convert the video to MP4 (H.264) and try again.
Try another browser; Safari and Chrome support different codecs.
Subtitles can still be exported even if the preview does not play.
Still stuck? Tell us your browser, device and what you saw. Contact →