A Complete Audio Workflow in Your Browser

A typical end-to-end audio task on UDT goes through several of these tools in a chain. You record a podcast episode in three takes, plus an intro music bed. You want to ship a single mastered file at a loudness target that won't get adjusted by Apple Podcasts or Spotify. Six tools, one continuous workflow.

Start with the Audio Trimmer on each take — set in and out points to drop silence and verbal flubs. Then run each take through the Audio Silence Remover to auto-shorten the breath gaps inside the recording — a 60-minute take usually drops to around 52. Drag the trimmed clips plus the intro bed into the Audio Merger, reorder until the sequence is right, and pick a crossfade duration (250ms for voice-to-voice, 1–2 seconds for music-to-voice).

Once the merged episode is together, add a polish pass with the Audio Fade tool — a 2-second fade-in at the start, a 3-second fade-out at the end. Then run the Audio Normalizer with the Spotify or Apple Music preset (depending on where the episode will land first), and finish with the Audio Peak Limiter at -1dB ceiling — limit-after-normalize is the standard mastering chain and catches any transients the loudness boost pushed near the ceiling. Finally, compress to MP3 at 128kbps with the Audio Compressor using the Podcast Music preset.

Other common chains: extract audio from a recorded video interview with the Audio Extractor, then run the MP3 through the Audio Transcription tool for show-notes prep (downsample first to 16kHz with the Audio Sample Rate Converter to speed up the Whisper run). Convert a FLAC archive to MP3 for portable playback via the Audio Converter. Trim a 30-second song segment with the Audio Trimmer, transpose to a singable key with the Audio Pitch Shifter, slow it down 10% for practice with the Audio Tempo Changer, fade both ends with the Audio Fade tool, and you have a custom ringtone or backing track. Split a dual-mic stereo podcast recording into left and right mono files for individual editing with the Audio Channel Tool.

The point of grouping these as a suite rather than just listing them is that every tool's output naturally becomes another tool's input. Pick the tool that matches your immediate next step; chain as far as your task demands.

Frequently Asked Questions about the Audio Suite

Are all 13 audio tools really free?+
Yes — every tool in the Audio Suite is free with no time limits, no file size caps, no watermarks, and no signup. The site is supported by ads elsewhere; the tools themselves are unrestricted.
Do my audio files ever leave my device?+
No. Every Audio Suite tool runs FFmpeg.wasm — the WebAssembly build of FFmpeg — entirely in your browser. The 32MB engine downloads once across the whole suite and caches; after that, tools work offline. Your files never touch a server.
Why does the first run download 32MB?+
FFmpeg.wasm is the WebAssembly port of FFmpeg, the same engine used by most desktop audio tools. It downloads once to your browser cache, then runs every operation locally without re-downloading. Switching between Audio Suite tools doesn't trigger another download — they all share the same cached engine. The Audio Suite shares the cache with the Video Suite, too.
Which audio formats are supported?+
MP3, WAV, AAC, OGG (Vorbis and Opus), FLAC, and M4A — covering essentially every file you might come across. The converter and compressor expose all of these; the trimmer, merger, fade, and normalizer preserve the source format by default or let you override.
What's the maximum file size?+
Limited by browser memory rather than any tool-imposed cap. Most modern laptops handle 1–2GB audio files comfortably; phones cap around 500MB. For multi-hour audiobook files or DAW project exports above 2GB, a desktop FFmpeg install will be faster.
Can I chain tools together (e.g., trim → normalize → compress)?+
Yes. Each tool exports a downloadable file you can immediately drop into another tool. Common chains: Trimmer → Compressor (cut to length, then shrink for distribution), Merger → Normalizer (stitch episodes, then match loudness), Extractor → Compressor (pull audio from video, then ship as MP3).
What's the underlying engine and license?+
FFmpeg.wasm v0.12.x with @ffmpeg/core v0.12.6, served from jsDelivr CDN. FFmpeg itself is LGPL-licensed; the wasm wrapper is MIT. UDT serves the engine unmodified and documents the version on every tool page — this is the LGPL-compliance posture.
Will the output be watermarked or have any quality cap?+
No. None of these tools add a watermark or impose a quality cap. The free tools elsewhere that do so are using both as upsell pressure — we'd rather just serve ads on the surrounding pages.

Written by Derek Giordano · Part of Ultimate Design Tools

Working with Other Media?

Adjacent UDT suites and tools that pair naturally with the Audio Suite — Video tools for source extraction, AI Audio Transcription for show notes, PDF for document workflows:

Video Tools →
17-tool Video Suite — compress, convert, trim, auto-subtitle, stabilize, color grade, more.
Audio Transcription →
Whisper-based AI speech-to-text in your browser — 99 languages, SRT/VTT/TXT export.
PDF Editor →
20-tool PDF suite — edit, sign, merge, redact, OCR.