“Audio to JSON” is an umbrella phrase. A podcast publisher may want ID3 tags, a developer may need sample-rate validation, and another user may expect a transcript. Only the first two are metadata extraction.
ChangeThisFile has evidence-backed MP3 to JSON and WAV to JSON routes. Both inspect the file's technical properties; neither claims to transcribe spoken audio.
MP3 metadata as JSON
MP3 files may contain title, artist, album, track, genre, date, artwork-related tags, duration, codec profile, bitrate, sample rate, and channel information. The exact result depends on which ID3 tags the file actually contains. Missing tags cannot be reconstructed from the audio signal by a metadata probe.
WAV metadata as JSON
WAV inspection focuses on technical properties such as PCM or compressed codec, sample rate, bit depth, channel count, channel layout, duration, and container chunks. WAV often has less standardized descriptive tagging than MP3, so the output is primarily useful for production checks and audio-pipeline validation.
Transcription and waveform data are different jobs
Speech-to-text analyzes audio content and produces timed words or segments. A waveform export decodes samples and can create a very large numeric array. Loudness, beats, and spectral features require signal analysis. None of those should be promised by a metadata-to-JSON route. Choose MP3 to JSON or WAV to JSON only when technical file data is the goal.
Use MP3 to JSON for MP3 tags and stream details, or WAV to JSON for sample rate, channels, bit depth, codec, and duration. If the desired JSON contains spoken words or per-sample values, you need a transcription or signal-analysis workflow instead.