GSM to OPUS converter
Convert GSM to OPUS in seconds, free and unlimited. No upload, no sign-up, no watermark: your audio never leaves your device.
Last updated
Quick answer: To convert GSM to OPUS, add the GSM file to the iHateFiles GSM to OPUS converter and press Convert. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. GSM is a format most software has stopped opening. OPUS is not.
Should you convert GSM to OPUS?
A safe conversion: GSM and OPUS are both lossless, so this is a change of container rather than a change to the picture.
Nothing is discarded
GSM and OPUS are both lossless, so every pixel survives the move intact. Convert back and forth as often as you like; the image does not degrade.
GSM and OPUS side by side
| GSM | OPUS | |
|---|---|---|
| Compression | Lossless | Lossless |
| Transparency | No | No |
| Animation | No | No |
| Written here | No | Yes |
What usually goes wrong
About the GSM. The quality ceiling is the codec, not the file. Converting to a higher bitrate cannot add back a frequency range that was never captured.
About the OPUS. Opus at 64 kbps sounds better than MP3 at 128, so the bitrate you are used to is roughly double what you need here.
How to convert GSM to OPUS
- Add your GSM file. It is read from your disk and stays there.
- Check the settings. The output format is already set to OPUS.
- Press convert and the OPUS file is saved back to your device.
Questions
How do I convert GSM to OPUS?
Open this page, add your GSM file, and press convert. The file is decoded and re-encoded by your own browser and saved back to your device. Nothing is uploaded.
Is this GSM to OPUS converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Will converting to OPUS lose quality?
OPUS is a lossy format, so some detail is discarded. The quality control on this page decides how much. The default is set high enough that most people cannot see the difference.
Can I convert several GSM files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.