Best use case
Use it when you need a fast browser workflow with clear input, visible output, and a concrete verification step.
REVIEWED LOCAL BROWSER WORKFLOW · WAV OUTPUT
Audio Cutter Online
· Reviewed public tool · English-only · WAV output
Trim browser-decodable audio locally, preview the exact range, then create a verified 16-bit PCM WAV with input/output SHA-256 and downloadable JSON and Markdown receipts.
No upload workflow
Waveform handles
Exact bytes + SHA-256
JSON + Markdown receipts
No signup
Media
Audio Cutter Online Decode locally, select and preview an exact range, then unlock a WAV download only after byte-level integrity verification.
What this tool does
- visual waveform editor
- millisecond start and end controls
- selection preview before export
- 16-bit PCM WAV output from the exact frame-aligned range
- browser audio decoding where supported
- no FastTool application upload
- input/output SHA-256 and exact byte lengths
- downloadable JSON and Markdown receipts
- stale output and download locking
- clear unsupported-format message
PREMIUM TOOL STANDARD
What the Audio Cutter proves before download
It keeps the claim narrow: browser-local decoding, an exact frame-aligned range, structurally valid PCM WAV bytes, input/output SHA-256, replay, and downloadable receipts.
Proof before trust
Run the labeled synthetic fixture first. The WAV and receipts remain locked until header, byte-length, and hash checks finish; changing the range makes prior proof stale.
Privacy boundary
Prefer local or non-sensitive input. Keep passwords, private keys, regulated records, and client data out unless the page explicitly fits that use.
Do not use for
Do not use it as a substitute for expert review when the output affects money, safety, legal rights, medical choices, or production systems.
AI agent handoff JSON
{
"tool": "Audio Cutter Online",
"canonical_url": "https://fasttool.app/tools/audio-cutter/",
"category": "Media",
"best_for": "Use it when you need a short local audio trim with waveform preview, WAV download, replay proof, and a receipt.",
"input_boundary": "Start with sample or non-sensitive data. Do not paste secrets, regulated records, or irreversible production values unless the tool explicitly fits that use.",
"output_checks": [
"Confirm the replay preview matches the intended selected range.",
"Use the WAV download and copied receipt only after checking edge cases.",
"Keep the original input when the job involves files or production data."
],
"not_for": "Do not use it as a substitute for expert review when the output affects money, safety, legal rights, medical choices, or production systems.",
"agent_instruction": "If an AI agent uses this page, it should cite the canonical URL, describe the input it used, report the visible output, and state what remains unverified."
}
PUBLIC EVIDENCE CONTRACT
Sample input, expected output, and safe-use boundary
This page gives a concrete control input, an expected result, real browser limitations, and a not-for boundary before the visitor uses a real file.
Sample input
Clearly labeled synthetic 4-second, 330 Hz mono PCM WAV. It is a fixture, not a user recording or claimed case study.
Expected output
A 16-bit PCM WAV unlocks only after structural and exact-byte checks. Replay, WAV, JSON receipt, and Markdown receipt remain tied to the current range.
Proof checks
- Waveform, number fields, preview, and receipt use the same frame-aligned range.
- Input/output SHA-256, exact bytes, media type, sample rate, channels, and receipt-core SHA-256 are explicit.
- Changing input or range locks stale downloads; cancel/reset retain no unfinished artifact.
- Browser decode errors and the truthful WAV-only output boundary are explicit.
When not to use it
Not for forensic audio, music mastering, copyrighted extraction without rights, or confidential recordings on untrusted devices.
Privacy boundary: Audio bytes, decoded samples, filename, selection, and hashes stay inside this browser tool. Page analytics can receive only allowlisted event metadata—never raw audio, filename, range, or hash. Do not use regulated or confidential media on an untrusted device.
COMMON QUESTIONS
Before you process a real file
How do I cut an audio file?
Choose audio, drag or type the start and end time, preview the selection, then create the verified WAV. Download buttons unlock only after the exact byte and SHA-256 checks finish.
Why is the output WAV?
The browser can reliably write WAV from decoded audio. WAV is used because the browser can deterministically write and verify PCM bytes; this tool intentionally does not promise MP3 output.
Does it upload my audio?
Standard trimming happens in your browser tab without uploading to a FastTool application server.
Which files work best?
WAV and common MP3 files are most reliable. Very large or unusual codecs may fail to decode in the browser.
Methodology, sources, and limitations
Audio Cutter reads the chosen file with the File API, decodes it through Web Audio, draws the decoded waveform on Canvas, writes the selected sample frames as 16-bit PCM WAV, and computes exact SHA-256 values with Web Crypto. It does not use MediaRecorder, an upload service, or an optional codec encoder.