Knowing exactly what is inside an audio file matters more often than it seems. A podcast host might reject an episode recorded at the wrong sample rate, a musician might need to confirm a mastered file is genuinely 24 bit rather than 16 bit upsampled to look that way, and anyone archiving old MP3s might want to see what artist and album information, if any, actually survived inside the file itself.
Every piece of information shown here is read directly from the file's own bytes and from what the browser's audio decoder reports, so what you see reflects the actual file rather than a filename guess or a database lookup.
What this audio metadata viewer reports
Duration, sample rate and channel count come directly from decoding the file through the Web Audio API, so they reflect the audio exactly as any player would interpret it, regardless of what a filename or a music library's own database claims. A file that shows 48000 Hz and two channels is genuinely stereo at that rate, no matter what it is labelled.
Bit depth is different, because it can only be read directly from an uncompressed WAV file's own header. Compressed formats like MP3, AAC and OGG do not store audio at a single fixed bit depth the way WAV does, since their compression works in the frequency domain rather than storing linear samples, so bit depth is reported as not applicable for those formats rather than a guessed or invented number.
- Duration, sample rate and channel count, decoded directly from the audio.
- Bit depth, read from the file header when the source is WAV, marked not applicable otherwise.
- An estimated bitrate calculated from file size and duration together.
- ID3 tags such as title, artist, album and year, when the file is an MP3 that has them.
Why the bitrate is only an estimate
If you just want to view audio bitrate without opening a full editor, keep in mind that a true bitrate figure comes from an encoder's own settings, which is not information a browser can read back out of an arbitrary file. What this tool reports instead is calculated by dividing the file's total size by its duration, which gives a genuinely useful approximation for most files but is not identical to the number an encoder would report about itself.
The estimate includes the container's own overhead, such as ID3 tags, chunk headers and any embedded artwork, which a dedicated encoder's bitrate figure typically excludes. For a file with a large embedded cover image, the estimated bitrate can read noticeably higher than the audio stream's actual encoded rate, which is worth keeping in mind when the number looks unexpectedly large.
Reading ID3 tags from an mp3 id3 tag reader
MP3 files can carry a block of metadata called an ID3 tag, stored either near the start of the file as ID3v2 or in the last 128 bytes as the older ID3v1 format. This tool reads the ID3v2 header directly, parsing frames for the title, artist, album, year and genre when they are present, and understands the common version 2.3 and 2.4 tag layouts that the overwhelming majority of MP3 files in circulation actually use.
Not every MP3 carries tags at all, and some files use the considerably older and less common ID3v2.2 layout, which this tool does not parse. When no tags are found, the viewer says so plainly rather than showing blank fields that might be mistaken for missing data on the file itself.
How this audio metadata viewer reads the file
Two separate passes read the file. The first hands the raw bytes to the Web Audio API's decodeAudioData, which returns an AudioBuffer exposing duration, sample rate and channel count. The second reads the file's raw bytes directly, looking for a WAV header's format chunk to extract bit depth, or an ID3v2 header's frames to extract tag text, neither of which the audio decoder itself exposes.
Both passes run entirely inside your browser tab using the File and Web Audio APIs, with no server involved at any point, so inspecting a private or unreleased recording never risks it leaving your device.
How to view audio metadata
- 1
Add your audio file
Drag an audio file onto the drop area, or click it to browse. MP3, OGG, FLAC, M4A, AAC and WAV are all accepted.
- 2
Review the decoded details
Duration, sample rate, channel count and estimated bitrate appear as soon as the file finishes decoding.
- 3
Check bit depth and ID3 tags
Bit depth appears for WAV files, and any ID3 title, artist, album or year appears for tagged MP3 files.
- 4
Copy or note the details
Use the reported values directly, since nothing further needs to be exported or downloaded.
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Sources and further reading
Frequently asked questions
Common questions about the audio metadata viewer.
Bit depth only applies to uncompressed formats like WAV, which store every sample at a fixed number of bits. Compressed formats such as MP3, AAC and OGG encode audio in the frequency domain and do not have a single fixed bit depth to report, so showing not applicable is more accurate than inventing a number.
It is calculated from the file's total size divided by its duration, which is a close approximation for most files but includes container overhead such as tags and any embedded artwork that a dedicated encoder's own bitrate figure would exclude. For a typical file without large embedded images, the estimate is usually within a few percent of the true encoded rate.
Yes, once the page has loaded, every part of the process runs locally using the Web Audio API and the File API. No part of reading duration, sample rate, bit depth or ID3 tags requires a network request, so it continues to work even if your connection drops.
Not every MP3 file has tags filled in for every field, and some files have no ID3 tags at all. This tool reports exactly what it finds in the file's own bytes rather than filling in a guess, so an empty field genuinely means that piece of information was never stored in the file.
Yes. Sample rate, channel count and duration are read the same way for every supported format, including WAV, and WAV additionally gets a bit depth reading directly from its header, which compressed formats cannot provide.
No. Both the audio decoding pass and the raw byte inspection for bit depth and ID3 tags happen entirely inside your browser tab. The file is never transmitted anywhere, which you can confirm by checking your browser's network panel while inspecting a file.