NEW · FFmpeg.wasm · 100% Browser-Based

Audio Sample Rate Converter

Convert audio sample rates with high-quality resampling — 44.1k, 48k, 96k, 192k, 22.05k, 16k, 8k, or any custom rate. Useful for matching DAW project sample rates or downsampling for legacy systems. FFmpeg.wasm runs locally. No upload, no signup, no watermark.

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Drop an audio file
MP3 · WAV · AAC · OGG · FLAC · M4A
Files stay on your device · Never uploaded

Related Tools on UDT

Audio Converter →
Convert between MP3, WAV, AAC, OGG, FLAC, and M4A — handles codec changes.
Audio Compressor →
Compress with bitrate/quality presets — MP3, AAC, Opus.
Audio Normalizer →
EBU R128 loudness normalization to broadcast standards.
All Audio Tools →
Browse the full Audio Suite — 13 tools, all in-browser.

Why Do This in Your Browser?

Sample rate conversion happens implicitly all the time — every codec change involves a potential resample, every DAW import that doesn't match the project rate gets converted on the fly. But sometimes you need to do it explicitly: a 44.1kHz mix needs to deliver to a 48kHz film post-production pipeline, a 96kHz studio session needs to ship as 44.1k for streaming, a 48kHz voice recording needs to drop to 16k for a Whisper transcription run.

Explicit conversion separates the codec/container question (which the Audio Converter handles) from the sample-rate question. FFmpeg's `aresample` filter, combined with the `swr` (software resampler) high-quality preset, produces conversions clean enough that the average listener cannot distinguish them from native-rate audio. This tool exposes preset buttons for the common targets plus a custom-rate input.

How It Works

Drop an audio file. Pick a target rate — the preset buttons cover the most common: 44.1kHz (CD audio, music streaming), 48kHz (video / film standard), 96kHz (high-resolution audio), 192kHz (very high-res, archival), 22.05kHz (low-bandwidth speech), 16kHz (telephony, Whisper input), 8kHz (very low quality, retro). Or type any rate from 4000 to 384000 Hz in the custom field.

FFmpeg applies `-ar TARGET_RATE -af aresample=resampler=soxr:precision=28` to invoke the SoX-quality resampler at high precision. Output sample rate is the new target; codec stays the same as the source unless you also change extension. Pre-conversion and post-conversion sample rates are displayed alongside the output.

Tip: For changing codec or container in addition to sample rate, use the Audio Converter — it handles both. To check loudness after downsampling (which can affect perceived volume), the Audio Normalizer brings the result to target.

Common Use Cases

DAW Project Rate Matching
Convert imported audio to match the host project's sample rate before importing. Prevents implicit resampling artifacts during mixdown.
Streaming Delivery
Convert high-rate studio masters (96k or 192k) down to 44.1k for music streaming services. Required for some delivery specs.
Whisper Input Prep
Downsample audio to 16kHz mono before running through Whisper. Reduces preprocessing time and matches Whisper's native rate.
Telephony / IVR
Convert audio prompts to 8kHz for telephony systems. The legacy rate for voice over copper lines.
Film Post-Production
Convert 44.1k music to 48k for film/TV delivery. Standard industry workflow.
Archive Format Migration
Resample 16-bit/44.1k CD rips up to 24-bit/96k for high-resolution archival before storing in a library.

How We Compare

Honest read on free, paid, and self-hosted options for this kind of job:

UDT Audio Sample Rate Converter (this tool): Free, browser-based, FFmpeg.wasm aresample with SoX-quality precision. Preset buttons + custom rate input. No upload, no watermark, no signup.
Audacity (desktop): Free, full audio editor with Tracks > Resample. This browser tool is the focused alternative — no install, no project.
SoX (command-line): Free, gold-standard CLI resampler. Same underlying algorithm as this tool's high-precision mode.
Adobe Audition: Creative Cloud $20+/mo. Edit > Convert Sample Type. Higher quality at extreme conversions.
FFmpeg CLI: Free, command-line; same engine as this tool. -ar 48000 -af aresample=resampler=soxr. This is FFmpeg with a UI.
Online resamplers (cloud): Several free options. Most require upload and limit file size. UDT runs entirely in your browser.

Frequently Asked Questions

Is this audio sample rate converter really free?+
Yes — completely free, no watermark, no time limits, no signup. The site is supported by ads elsewhere; the tool is unrestricted.
What's the difference between this and the Audio Converter?+
The Audio Converter changes codec and container (MP3 to WAV, AAC to OGG, etc.) and incidentally may resample. This tool changes only the sample rate — codec and container stay the same. Use this when you need explicit rate control without touching the encoding.
Which sample rate should I pick?+
44.1kHz for music delivery (streaming, CD, downloads). 48kHz for video/film delivery. 96kHz or 192kHz for high-resolution archival or studio masters. 16kHz for Whisper or other speech AI input. 8kHz for telephony. The presets cover all common cases.
Does converting to a higher sample rate improve quality?+
No. Upsampling cannot create information that wasn't in the original file. Going from 44.1k to 96k makes the file bigger without making it sound better. Upsampling is occasionally useful for keeping a consistent rate across a project, but it's not a quality boost.
What's the quality of the resampling algorithm?+
FFmpeg's aresample with the SoX (soxr) backend at precision=28 is essentially transparent for typical material. The same quality you'd get from running SoX directly via command line. Audibly indistinguishable from native-rate audio in blind tests.
Are my audio files uploaded anywhere?+
No. FFmpeg.wasm runs entirely in your browser. The 32MB engine downloads once and caches; after that, the tool works fully offline.
What's the maximum file size?+
Limited by browser memory. Most laptops handle 1–2GB audio files comfortably; phones cap around 500MB.
What's the underlying engine and license?+
FFmpeg.wasm v0.12.x with @ffmpeg/core v0.12.6 (aresample filter with SoX-quality backend). FFmpeg itself is LGPL-licensed; the wasm wrapper is MIT.