AnyTool
Your files never leave your device. All processing happens locally in your browser.

How do I add a fade-in and fade-out to audio online without uploading it?

Open AnyTool's Audio Fade In/Out, drop in your file, and drag the fade-in and fade-out handles directly on the waveform while a live preview plays the exact ramp. Choose from six curve shapes (linear, logarithmic, exponential, quarter-sine, half-sine and equal-power), add a single-file crossfade at a split point, and export WAV, MP3, M4A, OGG or FLAC. Everything runs in your browser with the Web Audio API and a self-hosted ffmpeg engine — no upload, no watermark, no size cap, no CDN.

  • Draggable fade-in/out handles on the waveform with live preview
  • Six fade curves plus a single-file equal-power crossfade
  • Fade presets (podcast intro/outro, music outro, DJ) and batch + ZIP
  • 100% in your browser — no upload, no watermark, no size cap, no CDN

What is

Audio fade

A fade gradually raises (fade-in) or lowers (fade-out) the volume of audio over a set time, following a curve such as linear, logarithmic or equal-power. A crossfade overlaps the end of one section with the start of another so they blend smoothly. A client-side fade tool computes the gain envelope and previews it in the browser with the Web Audio API, without uploading the file.

Audio Tools

Related terms

fade curvecrossfadeequal-powergain envelopewaveform

How to Add Fade In and Fade Out to Audio

Add fades and crossfades to an audio file in your browser.

20 secWeb browser
  1. 1

    Add audio

    Drop in any audio file — it stays on your device.

  2. 2

    Set the fades

    Drag the fade handles on the waveform, pick a curve, and loop the region to hear the ramp.

  3. 3

    Export

    Download as WAV, MP3, M4A, OGG or FLAC — nothing is uploaded.

Result: An audio file with fades

Frequently Asked Questions

No — the fade runs entirely in your browser.

The file never leaves your device and there is no size cap or watermark, unlike WuTools (50 MB), Clideo (watermark + 500 MB) or VEED (watermark).

Yes — six curves including logarithmic, exponential and equal-power.

The fade is computed as a gain curve and applied identically in preview and export, so what you hear is what you download — most fade tools offer one or two curves only.

Yes — drop a split point and the two halves blend with an equal-power crossfade.

One-click single-file crossfade overlaps the tail and head at the split with an equal-power curve; no client-side competitor in this space offers it.

Detailed Explanation

Methodology

How the Audio Fade In/Out Works

AnyTool fades audio entirely in the browser with the Web Audio API. The file is decoded once to draw a peak waveform with draggable fade-in and fade-out handles (and an optional crossfade split marker). The chosen curve — linear, logarithmic, exponential, quarter-sine, half-sine or equal-power — is built as a Float32 gain curve and applied with GainNode.setValueCurveAtTime, so the live preview is bit-identical to the export. The render runs in an OfflineAudioContext with the same curve; WAV is written directly, and a self-hosted single-threaded ffmpeg.wasm engine (bundled core, no CDN) encodes MP3 (libmp3lame), M4A (AAC, +faststart), OGG (libvorbis) or FLAC with metadata passthrough. Batches apply the same fade and download as a ZIP.

  • Runs client-side — the audio is never uploaded
  • Draggable fade handles on a Web Audio waveform
  • Six curves applied identically in preview and export
  • Single-file equal-power crossfade at a split point
  • Self-hosted ffmpeg core (bundled) — no CDN
  • Batch + ZIP; export WAV/MP3/M4A/OGG/FLAC
Privacy & Security

Privacy vs Cloud Fade Tools

WuTools caps files at 50 MB, Clideo adds a watermark and a 500 MB cap, VEED and online video editors watermark free exports, and audiotrimmer uploads to a server. AnyTool fades on the device, so the file never leaves the browser, with no size cap, watermark or sign-up. It also offers six curve shapes and a one-click single-file equal-power crossfade — beyond the linear-only or two-curve rivals and the timeline-based crossfade that competitors require.

Audio fades: AnyTool vs typical tools
CapabilityAnyToolTypical tools
Data handlingIn your browserOften uploaded
Fade curvesSix shapesOften 1-2
Single-file crossfadeYes (equal-power)Rare
Draggable handlesYes (waveform)Often slider-only
Watermark / capNoneCommon

AnyTool is a privacy-first client-side fade tool — fading runs locally and nothing is uploaded.