Audio Metadata Viewer
Inspect any audio file to see its codec, sample rate, channels, duration, bitrate, and full FFmpeg probe output. Useful for verifying encoder settings, debugging compatibility issues, and learning what's inside an audio file.
About Audio Metadata Viewer
Inspect any audio file to see its codec, sample rate, channels, duration, bitrate, and full FFmpeg probe output. Useful for verifying encoder settings, debugging compatibility issues, and learning what's inside an audio file.
All analysis happens entirely inside your browser using the Web Audio API. Your audio file never leaves your device — there is no upload, no account, no tracking. Closing the tab fully erases the file from memory.
Browser-based audio analysis trades a little speed for total privacy. Server tools can crunch big lossless files faster on dedicated CPUs, but they require uploading your file. Here, decoding and analysis run on the same hardware you're holding.
Related tools
About Audio Metadata Viewer
Audio Metadata Viewer runs the audio editing and conversion job locally inside your browser. Inspect any audio file to see its codec, sample rate, channels, duration, bitrate, and full FFmpeg probe output. Useful for verifying encoder settings, debugging compatibility issues, and learning what's inside an audio file. The work happens on your machine, the result is generated on your machine, and the page exposes the controls you need to drive it without burying them in menus.
Typical users of Audio Metadata Viewer include teachers recording lessons, voice-over artists exporting takes and students preparing oral submissions. The thread connecting all of them is the same: a focused audio editing and conversion task that fits cleanly into a browser tab and benefits from a tool with sensible defaults and minimal setup.
The execution path is auditable from the page itself: open developer tools, switch to the Network tab, run a job. The requests you see are static-asset GETs for the engine and the page resources. The actual work is JavaScript code running against the bytes already in your tab's memory.
From a technical standpoint, Audio Metadata Viewer is JavaScript and standard browser APIs running in your tab. The browser is the runtime; the page is the interface. Inputs accepted: MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA. Maximum input size: 200 MB per run.
Most people land on Audio Metadata Viewer via a search at the moment they actually need the tool. That shapes the design: the page is a single screen with the input on one side, the controls in the middle, and the result on the other, so a first-time visitor can complete the job without reading documentation.
Audio Metadata Viewer sits in a small group of related tools. Useful neighbours include Audio Metadata Editor, Audio Metadata Remover, Audio Duration Calculator, and Audio Bitrate Calculator. They are designed to compose: the output of one is a sensible input to the next, so a multi-step task is usually a sequence of single-click operations.
The download is delivered as `{name}-edited.{ext}` the moment processing completes — no email link, no "your result will be ready in 5 minutes" queue, no expiry timer. The file is generated in your browser and saved by your browser's normal download flow.
The only practical limit is the 200 MB per-file ceiling, which keeps the tool responsive across a wide range of devices. Run the tool ten times in a row, run it ten thousand times — it behaves the same way and produces the same quality of result.
Some notes on the design of Audio Metadata Viewer. The page is intentionally narrow: one input, the controls relevant to the task, and one output. Adding unrelated features would make the common case slower for the majority of users, so the surface is held to what people actually use.
A short note on how Audio Metadata Viewer came to look the way it does: every iteration started by watching how someone unfamiliar with the tool actually used it, then removing whatever got in their way. That is why the upload area dominates the screen, the run button is bigger than the secondary controls, and the result panel is unmissable when the job finishes.
Tips from users who reach for Audio Metadata Viewer regularly: process one input first to confirm the settings produce what you expect before committing to a batch; treat the page as the working surface and avoid leaving large jobs running in a backgrounded tab where the browser may throttle JavaScript; and if a particular file fails, check whether the source is intact by opening it in its native viewer — most "tool errors" are actually input errors.
For most failure modes, refreshing the page and re-running the job is enough — the engine has no persistent state to corrupt. If the same input fails twice in a row, the input itself is most likely the problem (a truncated file, an unexpected variant of the format, or a stream the engine does not recognise).
If you also use a command-line tool for audio metadata viewer, Audio Metadata Viewer is a convenient alternative for the times you are on a different machine or helping someone who is not comfortable in a terminal. The output is a standard file in the format documented above.
Audio Metadata Viewer is one of many single-purpose tools in the catalog. Each is built around the same single-page model. Use this one, close the tab, and come back the next time you need the same job done. None of the tools require prior knowledge of the others — each page is self-contained.
How it works
- 1Reach the Audio Metadata Viewer page in your browser to begin.
- 2Drop a MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA file onto the upload area, or click to pick one from your device.
- 3Adjust the options to match what you need. Sensible defaults cover the most common case, so you can usually skip this step.
- 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
- 5Grab the output named `{name}-edited.{ext}` as soon as the run completes. You can also copy the result instead of downloading if the next tool in your workflow accepts pasted input.
- 6Repeat the process for additional inputs whenever you need to. The page stays loaded, so subsequent runs are quick.
Common use cases
- Record a quick test tone to verify a microphone setup using Audio Metadata Viewer.
- Stitch several voice notes into a single playable file.
- Boost a quiet interview recording to a normal listening level.
- Convert a voice memo into a format your editor can open.
- Compress a music demo small enough to share over messaging.
- Re-encode a lossless track into a portable format for the gym.
- Normalise loudness across an episode so listeners do not reach for the volume.
- Extract the audio from a video so it can be edited separately.
- Split a long mixtape into individual track files.
- Convert a band's rough mix into a format mastering software accepts.
FAQ
How does the viewer work?
A WebAssembly build of FFmpeg loads in your browser and runs an `-i` probe against your file. The probe output (the same one you'd get from running `ffprobe` on a desktop) is parsed into structured panels for easy reading. The full raw output is also available as a downloadable text report.
What information do I see?
Container info (file name, size, duration, overall bitrate). Audio stream info (codec, sample rate in Hz, channel count, channel layout, bit depth). Metadata tags (title, artist, album, year, genre, custom tags). Embedded album art (if present, dimensions and format). Chapter markers (for chaptered audiobooks).
When is this useful?
Verifying that an export came out with the settings you intended, debugging "why won't this file play?" issues by comparing encoder/sample rate/channel mismatches, learning about an unknown audio file, checking metadata before sharing or uploading, and preparing files for strict format requirements (broadcast, archive).
Why does my file show "Unknown" for some fields?
Some containers don't expose every field. Some encoders don't fill in every metadata tag. FFmpeg WASM occasionally fails to parse exotic formats. The structured panels show what we can extract reliably; the full probe report contains everything FFmpeg saw including parse errors.
Is this the right tool for editing tags?
No — this only views. To change tags (title, artist, etc.), use the Audio Metadata Editor. To remove all tags for privacy, use the Audio Metadata Remover.
How big a file can I inspect?
Up to 200MB. Probing is very fast (a few seconds even for hour-long files) because no audio decoding happens — just header parsing.
Why is in-browser audio processing slower than online tools?
Server-side tools use multi-threaded native FFmpeg running on dedicated CPUs with fast disks and parallel pipelines. Our engine is FFmpeg compiled to WebAssembly, which runs single-threaded inside your browser tab and has no access to native hardware acceleration. That makes browser-based jobs typically 3–8× slower than a server. The trade-off is total privacy: your audio file is never uploaded, never logged, and never stored — closing the tab erases everything from memory immediately. For most clips up to a few minutes the wait is small, and for sensitive recordings (voice memos, drafts, confidential meetings) the privacy gain is well worth it.
Is my audio uploaded?
No. Everything runs entirely inside your browser tab using FFmpeg compiled to WebAssembly. The file is read into local memory only, processed in the same tab, and the result is offered as a direct download. Nothing is transmitted to any server, no account is required, no analytics are tied to your file, and closing the tab discards every byte from memory.
How big a file can I process?
The file picker accepts audio inputs up to about 1 GB, which is well above what mainstream "free tier" online converters allow. The real ceiling is your device — everything runs inside your browser tab, which shares memory with the rest of the page. Most podcasts, songs, and voice memos sit comfortably under that limit even on a phone. If a very large lossless WAV or FLAC ever fails, trim it first or transcode to MP3 / Opus to bring the size down before re-running the tool.
Which audio formats are supported?
MP3, WAV, OGG (Vorbis and Opus), FLAC, M4A (AAC), AAC, Opus, AIFF, and WMA all decode reliably via FFmpeg WASM. Output formats depend on the specific tool — most editing tools default to MP3 (universal) or WAV (lossless) but expose a format picker so you can pick the one that fits your downstream player or DAW.
Which browsers are supported?
Recent Chrome, Edge, Firefox, Safari, and other Chromium-based browsers all work. The tool relies on WebAssembly and SharedArrayBuffer, which require the page to be served over HTTPS with the right cross-origin headers — this site is configured correctly by default. On phones the same code runs but is slower than on a desktop because mobile CPUs are weaker.
Is there a watermark, sign-up wall, or usage cap?
No. The tool is completely free, requires no account, attaches no watermark, applies no usage caps, and shows no popup ads on your output. Because the work happens on your own device, there is no per-user quota for us to enforce — your hardware and browser memory are the only limits. The download is the file you would get from running FFmpeg locally, nothing more, nothing less.
How is Audio Metadata Viewer different from desktop apps that do the same thing?
Desktop apps usually have more advanced features but require installation, maintenance and (often) a licence. Paid online tools are convenient but route your file through their servers and gate downloads behind accounts. Audio Metadata Viewer sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common audio editing and conversion operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
Does Audio Metadata Viewer work on a phone or tablet?
Audio Metadata Viewer runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 200 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.
How long does Favtoo retain my data after using Audio Metadata Viewer?
Favtoo keeps no copy of your file because Favtoo never receives your file. Audio Metadata Viewer runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.
Will I notice a difference in the output from Audio Metadata Viewer?
Audio Metadata Viewer is built to preserve quality wherever the underlying audio format allows it. Operations that are mathematically lossless (e.g. structural transformations, lossless re-encoding) round-trip with no perceptible change. Operations that involve a lossy codec inevitably introduce small artefacts at the byte level, but the defaults aim at the sweet spot where output looks or sounds the same to a normal viewer or listener while still being meaningfully smaller or faster than the input.
What should I do if Audio Metadata Viewer fails on my file?
Failures usually fall into one of three buckets: the input is in an unsupported format, the input is over the size cap, or the input is structurally malformed (a truncated download, a partial export, or a stream the engine does not recognise). The first two are easy to confirm — check that your file is one of MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA and that it is below 200 MB. For the third, opening the file in its native viewer first is the fastest way to confirm the source is intact.
What is the maximum file size for Audio Metadata Viewer?
Inputs are capped at 200 MB per file, which keeps memory usage stable across phones, tablets and older laptops. You can run Audio Metadata Viewer as often as you need; every run produces a full-quality result.
Can I use Audio Metadata Viewer on documents that contain personal data?
Your file is processed inside your browser by standard browser APIs. The engine reads the file's bytes from your tab's memory, computes the result, and writes the result back into the tab. You can confirm what the page does by opening developer tools and watching the Network tab during a run — the requests you see are for the tool's static assets only.