How to Convert GSM to SPX — Quick & Free
Fast, instant GSM to SPEEX conversion. No signup required. Just drop your .gsm file and get .spx in seconds.
Batch Settings
About GSM to SPEEX Conversion
Short answer: yes, you can convert GSM to SPX online for free, and quality is well preserved with the right settings. Just upload your .gsm file to CocoConvert, pick SPX as the output, and click Convert. The whole process takes seconds.
Now for the details. GSM is a widely used file format. SPX is a widely used file format. Converting between these two formats lets you convert between formats quickly.
Your GSM file is decoded and re-encoded as SPX. Converting GSM to SPX maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert runs entirely online — no software to install, no account to create. Your files are encrypted during upload (TLS), processed on isolated servers in Germany, and permanently deleted after 24 hours. It works in Chrome, Safari, Firefox, Edge, and all mobile browsers.
Need to convert more than one file? Free users can do 5 per hour. Pro gets 100 per hour with files up to 5 GB each.
How to Convert GSM to SPEEX
- 1
1. Upload GSM
Drop your .gsm file onto the page (or tap "Browse" on mobile). Add multiple files for batch conversion.
- 2
2. Select SPX
Choose .spx from the output dropdown. Settings are pre-configured for best results.
- 3
3. Convert
One click. The server handles all the heavy lifting using FFmpeg and Sharp.
- 4
4. Download
Your .spx file is ready. Download it directly or get all files as a zip archive.
What Happens When You Convert GSM to SPEEX
Your GSM file is decoded and re-encoded as SPX.
Your GSM file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in SPX format
The converted file is ready for download
Format Comparison
GSM
.gsm file
| Extension | .gsm |
| MIME Type | audio/gsm |
| Category | Audio |
Speex
.spx file
| Extension | .spx |
| MIME Type | audio/ogg |
| Category | Audio |
Should You Convert GSM to SPEEX?
When to Convert
- ✓When you need a SPX file
Frequently Asked Questions
Is GSM to SPX conversion free?
Yes. CocoConvert offers free GSM to SPX conversion with generous daily limits — 25 minutes of processing time and up to 5 files per hour (250 MB each). Pro plans remove these limits.
How fast is GSM to SPX conversion?
Most files convert in 2–10 seconds depending on size. Large audio files may take 30 seconds. Batch jobs process in parallel for maximum speed.
What happens to my files after conversion?
Your uploaded GSM file and the converted SPX file are both automatically deleted from our servers within 24 hours. They are never shared, sold, or analysed.
Does converting GSM to SPX lose quality?
Converting GSM to SPX maintains high quality with CocoConvert's optimised encoder settings.
Can I convert SPX back to GSM?
Yes, CocoConvert supports SPX to GSM conversion as well. However, if the original conversion involved lossy compression, converting back won't recover the lost data.
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