The key and BPM values in the database are provided by Spotify who use their own estimation algorithms to find key and BPM. The analysis results you get from uploading audio files to this page come from different algorithms that are run on Tunebat servers. Due to the algorithms being different, sometimes the results are different. Also, it's possible that there are differences between the file you upload, and the file Spotify analyzes for a specific song.
The results you see on this page are estimates. The accuracy of these estimates has been measured across multiple large data sets and compared to several prominent commercial key and BPM detection algorithms. For some datasets this finder proved more accurate than existing commercial key and BPM detection tools. But for other data sets this finder was less accurate. Overall you can expect results from this finder to be as accurate as key and BPM finders found in other commercial softwares, more or less.
They are uploaded to Tunebat's analysis server where they are analyzed using audio processing algorithms. These algorithms output key and BPM which is reported back to you. Then the audio file is deleted from the Tunebat server. No audio files are kept by Tunebat longer than they are needed to complete the analysis.
MP3, WAV, FLAC, AAC, OGG, and M4A.
Yes. Currently there is a limit that's been put in place to prevent overloading the analysis server. If you'd like this limit removed please reach out to .
Currently no. However, if there is enough interest it could be made. If you're interested, please reach out to .
Make sure you are using one of the supported file types. Make sure the file is less than 75MB. If you have reached the upload limit, then wait 1 hour before trying to upload again. Make sure you've disabled any adblockers. If this doesn't address your case, then you can report the error to .