Free · RIFF/BWF inspector · byte-preserving export

BWF Metadata Editor

Inspect a WAV chunk by chunk, edit Broadcast Wave bext, common LIST/INFO fields and raw iXML, then verify that audio data and every untouched chunk survived byte-for-byte.

FILE STRUCTURE MAP

Broadcast Chunk Map

Inspect raw RIFF chunks before changing delivery metadata. The chunk map separates original fmt/data bytes from editable bext, INFO and iXML. Literal metadata stays text, and export waits for a verified build of the current WAVE.

Open the full signal breakdownCurrent WAVE, byte preservation and recipient checks

Broadcast WAV file
Start with the right material
Adding production descriptions, originator data, time reference, coding history and machine-readable project metadata to PCM or floating-point WAV deliveries.
Edit RIFF metadata
Understand the transformation
The current RIFF chunk table is parsed without audio decoding. Metadata is displayed as literal text; a verified rebuild copies fmt, data and untouched raw chunks, while a new source selection retires old downloads.
Preserved BWF
Verify the usable result
Visible chunk map and metadata validation plus an updated WAV and structured JSON chunk manifest.

Chunk integrity

Where this workflow stops

Support is limited to ordinary RIFF/WAVE files within browser memory limits. RF64, Wave64, compressed WAV variants and vendor-specific metadata semantics may require dedicated broadcast software.

THREE-PASS CHECK

Verify structure, fields and the receiving app

After selecting another WAVE, wait for that file; previous downloads are no longer current.
Build after your last field edit and inspect fmt/data/unknown exact plus the metadata before/after diff.
Keep the original, inspect WAV and JSON in the receiving workflow, and check playback separately; XML syntax is not vendor-schema validation.

RIFF-level visibility: See chunk ids, offsets, sizes, padding, hashes and hex previews instead of treating a Broadcast Wave as an opaque audio file.
Production metadata: Edit bext identifiers and 64-bit sample time reference, common INFO descriptions and an entire syntactically validated iXML document.
Verified preservation: fmt, audio data and untouched chunks are copied from original byte ranges and compared before WAV or JSON export becomes available.

How to edit Broadcast Wave metadata online

Open a local PCM or IEEE float RIFF/WAVE file, or generate the archive demo. Wait for the current source; a newer selection retires old downloads. Cancel file read or Retry selected file resolves an unfinished read.
Review the current chunk map: identifiers, sizes, padding, hashes and short hex previews separate the raw audio and format data from editable metadata.
Edit bext, INFO and iXML; validate fixed field lengths, the unsigned 64-bit sample time reference, UMID and XML syntax. Metadata is shown as literal text, not executed HTML.
Build after the last field edit, inspect fmt/data/unknown exact and the before/after diff, then download the current WAV and JSON manifest. Keep the original and inspect both in the receiving workflow.

Broadcast Wave metadata, not MP3 ID3 tags

The existing Metadata Editor edits ID3 frames attached to MP3 audio. BWF Metadata Editor works inside RIFF/WAVE: the Broadcast Audio Extension (`bext`), `LIST/INFO` subchunks and raw `iXML`. It never converts these structures into ID3 or decodes the audio payload.

What byte-preserving means here

The file is parsed into bounded RIFF chunks. Edited metadata chunks are rebuilt with corrected declared sizes and even-byte padding. The original raw bytes for `fmt `, every `data` chunk and every untouched or unknown chunk are carried forward and compared after reparsing the output. Missing edited metadata is inserted immediately after the first `fmt ` chunk in a deterministic order.

Supported boundary

This tool accepts PCM and IEEE float RIFF/WAVE, including the corresponding WAVE_FORMAT_EXTENSIBLE subformats. It deliberately refuses RF64, Wave64, compressed WAVE codecs, truncated chunks and malformed sizes. Files approaching RIFF's 4 GiB limit are outside the browser and container safety boundary.

Privacy: selected WAVE bytes remain in this browser. Parsing, XML validation, rebuilding, hashing and download preparation happen on this device.

Worked example: prepare a field-recording delivery

Generate archive demo to inspect a six-chunk PCM WAVE containing bext, iXML, INFO and an odd-sized JUNK chunk. Change Description to Session 07 take 3 and INFO Name / title to the receiving project's label. Keep the existing time reference, UMID and coding history unless your production requirements specify a change. Build verified WAV, review the metadata diff and the fmt/data/unknown exact indicators, then download both the edited WAV and metadata manifest JSON.

What the verification does and does not certify

The build reparses its output and compares the original raw format, audio-data and untouched chunks, including original padding bytes. Edited metadata is rebuilt with corrected RIFF sizes. This checks byte preservation, not the correctness of an originator identity or a broadcaster's delivery requirements. iXML validation checks XML syntax and refuses a DOCTYPE; it does not validate a vendor schema or understand every recorder-specific field. Do not enter seconds into a sample-count time reference, and keep its decimal digits intact rather than rounding through a spreadsheet number.

Recover without delivering an older WAVE

Selecting a new source immediately clears the old chunk map, editable fields and downloadable result. The source stays unavailable until that current read succeeds. Cancel file read or Escape prevents a late read from restoring it; Retry selected file or choose another WAVE to continue. Cancelling a build keeps loaded bytes and current edits but discards its result. Editing after a build invalidates downloads and requires another build. Leaving the page retires unfinished work; logical cancellation does not abort native disk I/O.

Before handing the files to another application

Keep an untouched original, reopen the downloaded WAV in the intended archive or production application and inspect the fields it actually reads. Compare the JSON's input/output chunk records with your required delivery, and verify playback separately. The editor never decodes or processes the audio. Input is capped at 200 MB and a conservative pre-read device budget can require a smaller file, especially on mobile. RF64, Wave64, compressed WAVE and malformed RIFF sizes remain outside this editor's boundary.

BWF Metadata Editor: quick answer and technical limits

Quick answer: A local RIFF/WAVE inspector and editor for Broadcast Wave bext, iXML and LIST/INFO metadata that preserves the source audio chunk during export.

Best for: Adding production descriptions, originator data, time reference, coding history and machine-readable project metadata to PCM or floating-point WAV deliveries.
How it works: The current RIFF chunk table is parsed without audio decoding. Metadata is displayed as literal text; a verified rebuild copies fmt, data and untouched raw chunks, while a new source selection retires old downloads.
What you get: Visible chunk map and metadata validation plus an updated WAV and structured JSON chunk manifest.

Know before you use it: Support is limited to ordinary RIFF/WAVE files within browser memory limits. RF64, Wave64, compressed WAV variants and vendor-specific metadata semantics may require dedicated broadcast software.

Privacy: Selected audio is processed in this browser and is not uploaded to AudioWrench. Normal page assets can still be requested as described in the privacy notice. Privacy details →

FAQ

How is this different from the MP3 Metadata Editor?

The MP3 Metadata Editor reads ID3 frames around MPEG audio. BWF Metadata Editor works on RIFF/WAVE chunks and exposes Broadcast Wave bext, LIST/INFO and iXML structures used in production, field recording and archives.

Will editing BWF metadata change the audio samples?

No. The data chunks and fmt chunk are copied from their original raw bytes and verified after rebuilding. Untouched and unknown chunks, including their original RIFF padding byte, are also checked byte-for-byte before export is enabled.

Which WAVE containers and encodings are supported?

The editor supports RIFF/WAVE with PCM or IEEE float fmt data, including their WAVE_FORMAT_EXTENSIBLE subformats. It does not currently support RF64, Wave64, compressed WAVE codecs or files whose RIFF chunk structure is malformed.

What is the bext time reference?

It is an unsigned 64-bit sample count describing the first sample position relative to the production timeline. AudioWrench reads and writes both 32-bit halves without converting the value through an unsafe JavaScript number.

Is my Broadcast Wave uploaded?

No. RIFF parsing, XML validation, metadata rebuilding, byte comparison and export run in this browser on your device.

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