Skip to main content

About Audio Metadata Editor

Audio Metadata Editor runs the audio editing and conversion job locally inside your browser. Edit the title, artist, album, year, genre, and other metadata tags of any audio file. The audio data itself is preserved unchanged via lossless stream-copy. Files are processed entirely in your browser with FFmpeg WebAssembly. 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.

The engine behind the page is standard browser APIs. It reads your file in-memory and writes the result back into the browser. Supported inputs include MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA. For 200 MB and below the work usually completes in seconds; larger files mostly depend on how much spare RAM your device has.

Most people land on Audio Metadata Editor 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.

The architecture is local-first by design. Once the page is loaded, you can disconnect from the network and the tool still completes the job. The processing stack — standard browser APIs and the small UI shell wrapping it — ships with the page itself, so the tool keeps working in offline conditions, on a captive-portal Wi-Fi, or behind a corporate proxy that limits what the tab can reach.

Constraints worth knowing about: inputs are capped at 200 MB to keep memory usage in a sensible range, one input is processed per run, and the tool must be loaded over HTTPS for the in-browser engine to work. These are properties of the architecture.

Audio Metadata Editor sits in a small group of related tools. Useful neighbours include Audio Metadata Viewer, Audio Metadata Remover, Audio Normalizer, and Audio Channel Splitter. 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.

Audio Metadata Editor is shaped around the recurring needs of two audiences: sound designers prototyping cues, who use it as a quick utility between bigger tools, and teachers recording lessons, who use it as their primary way of getting the job done. Both groups get the same defaults and the same speed.

Output handling is intentionally boring: Audio Metadata Editor produces `{name}-edited.{ext}` and triggers your browser's standard "save" behaviour. If you have a default download folder configured, that is where it will land. There is no Favtoo-side history of jobs you have run.

Some notes on the design of Audio Metadata Editor. 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.

Audio Metadata Editor is structured around the idea that a useful tool should be its own page. Open the page, do the work, close the tab — the page is the entire product. There is no onboarding flow because there is nothing to onboard into.

Tips from users who reach for Audio Metadata Editor 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.

Audio Metadata Editor runs as a regular web page, so there is no install step or permission grant before the first run. The page can be audited by viewing the source or by watching the developer-tools Network tab while a job runs.

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).

That is the whole tool. Use Audio Metadata Editor for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.

How it works

  1. 1Land on the Audio Metadata Editor page. The tool is ready to use the moment the page renders.
  2. 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.
  3. 3Adjust the options to match what you need. Sensible defaults cover the most common case, so you can usually skip this step.
  4. 4Hit the run button. standard browser APIs does the work in your browser tab.
  5. 5Save the output (`{name}-edited.{ext}`) when it is ready.
  6. 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.

Common use cases

FAQ

How does the editor work?

FFmpeg WebAssembly loads in your browser. The original audio stream is copied losslessly (`-c copy`) into a new file with your edited metadata. Because the audio is not decoded or re-encoded, there's zero quality loss and the operation is very fast — typically a few seconds per file.

Will the file size change?

Almost not at all — the audio data is identical to the source. Only the tag fields change. Adding a long album title or embedding new cover art might add a few KB; removing tags shrinks the file slightly. The audio bytes themselves are preserved unchanged.

Will I lose audio quality?

No. The tool uses FFmpeg's `-c copy` mode which copies the audio stream byte-for-byte without decoding. Quality is byte-perfect identical to your input file.

Which formats are supported?

MP3 (ID3v2 tags), M4A (MPEG-4 atoms), FLAC (Vorbis comments), OGG (Vorbis comments), WAV (LIST INFO chunks), Opus (Vorbis comments). Different formats use different tag systems internally; the tool handles the translation automatically.

Can I add or change album art?

This editor focuses on text tags. For album art changes, you can use the Metadata Remover to strip old art, then a different tool to embed new art (planned for future). Tagging tools like Mp3tag (desktop) handle this well.

How is this different from "Audio Metadata Remover"?

Editor lets you change tag values. Remover wipes them entirely (useful for privacy). Both preserve the audio quality identically.

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.

Why is my browser prompting me when I open Audio Metadata Editor?

Audio Metadata Editor only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.

Does Audio Metadata Editor work on a phone or tablet?

Audio Metadata Editor 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.

Is there a programmatic version of Audio Metadata Editor?

Audio Metadata Editor is a browser-only tool by design and does not expose a hosted API. The reason is the same as the privacy story: there is no Favtoo backend doing the work, so there is no service to call. If you need to script the same transformation, the underlying engine (standard browser APIs) is open-source and can be used directly from your own code.

Why use Audio Metadata Editor instead of a paid online tool?

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 Editor 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.

What does the error message in Audio Metadata Editor mean?

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.

Is Audio Metadata Editor licensed for business use?

Audio Metadata Editor can be used for personal and commercial work alike — there is no separate "business" licence to purchase. The output you generate is yours to use however you want, including in client deliverables, internal documents, or commercial products. Favtoo's only ask is fair, individual use; the tool is not designed to be embedded as a backend service or wrapped behind an API for resale.

Is Audio Metadata Editor really free?

Audio Metadata Editor is free to use. The processing runs in your browser, which keeps the per-user cost low enough that the tool can be offered openly. The download is the same file the engine produced — you can use it for as many runs as you need.

Audio Recorder

Record from your microphone directly in the browser. Pick quality (high, medium, low), toggle echo cancellation, noise suppression and auto-gain, then save to WebM/Opus or M4A/AAC. Audio is captured locally — nothing is uploaded.

Text to Speech

Type or paste text, pick a system voice, and listen instantly. Adjust speaking rate (0.5×–2×), pitch, and volume in real time. Uses your browser's built-in Web Speech API — no cloud TTS, no API keys, no costs.

Tone Generator

Generate a pure tone at any frequency from 20 Hz to 20 kHz. Pick a sine, square, triangle, or sawtooth waveform, choose duration, amplitude, and mono/stereo. Exports a 16-bit PCM WAV file at 44.1 kHz with built-in click-preventing fades.

Silence Generator

Generate a perfectly silent WAV file of any length from 1 second up to 1 hour. Pick mono or stereo, get a 16-bit PCM WAV at 44.1 kHz. Useful as padding between clips, intro silence, leader audio for video timing, or test material.

White Noise Generator

Generate white, pink, or brown noise as a 16-bit PCM WAV file. Pick noise type, duration up to 1 hour, amplitude, and mono/stereo. Useful for sleep, focus, masking distractions, audio testing, and as a backing layer for ambient music.

Metronome

A precise browser-based metronome powered by the Web Audio API. Set BPM from 30 to 300, choose a time signature, accent the first beat, and use tap-tempo to sync. Click timing is sample-accurate using lookahead scheduling — much steadier than typical JavaScript setInterval beats.

Audio Trimmer

Trim any audio file to a precise start and end time. Outputs a lossless stream-copy by default (no quality loss, very fast) or re-encodes to MP3, WAV, OGG, or M4A. Files are processed entirely in your browser with FFmpeg WebAssembly.

Audio Splitter

Split a long audio file into N equal-length parts and download them as a ZIP. Each part is named sequentially. Great for chapterizing audiobooks, podcasts, or long DJ mixes. Runs entirely in your browser with FFmpeg WebAssembly.

View all Audio Tools