How to change audio bitrate online — free, no upload
- Step 1Check the target platform's spec — Confirm the bitrate the destination wants (e.g. 'MP3, 128 kbps' for many podcast hosts, '256–320 kbps' for music distributors). Pick the closest of the five available targets.
- Step 2
- Step 3Drop the source file — Drag in your MP3, WAV, FLAC, M4A, OGG, Opus, or a video. All decode to PCM internally and re-encode to MP3 — the output extension is .mp3.
- Step 4Select the bitrate — Choose 320, 256, 192 (default), 128, or 64 kbps from the Bitrate dropdown to match the platform requirement.
- Step 5Process locally — Run the encode. FFmpeg writes a CBR MP3 with
libmp3lame -b:a. Time scales with duration and CPU, not connection speed. - Step 6Download and confirm — Download the MP3 and verify the reported bitrate matches what the platform asked for before you submit.
Common platform requirements vs. the right target
Illustrative targets mapped to the five available bitrates. Always confirm the destination's current spec; requirements change.
| Destination type | Typical spec | Best available target | Notes |
|---|---|---|---|
| Podcast host | MP3, 96–128 kbps | 128 kbps · podcast | Mono voice can sit lower; 128 kbps is the safe default |
| Music distributor | MP3, 256–320 kbps | 320 kbps · best | Use the source's full quality; lossless is better if accepted |
| Voice-note / chat | Small MP3 | 64 kbps · voice | Voice-tuned; keeps files tiny |
| General web embed | Balanced MP3 | 192 kbps · default | Good quality without bloating page weight |
| Audiobook | Spoken-word MP3 | 64–128 kbps | 64 kbps for plain narration, 128 kbps if music beds exist |
Input format to output mapping
All inputs converge on a single MP3 output. Grounded in encoderForExt and the fixed format default for this tool.
| Input you drop | Internal encoder used | Output you get |
|---|---|---|
| MP3 | libmp3lame | MP3 at chosen CBR |
| WAV (PCM) | libmp3lame | MP3 at chosen CBR (lossy from lossless) |
| FLAC (lossless) | libmp3lame | MP3 at chosen CBR (lossy from lossless) |
| M4A / AAC | libmp3lame | MP3 at chosen CBR |
| OGG / Opus | libmp3lame | MP3 at chosen CBR |
| Video (audio track) | libmp3lame | MP3 at chosen CBR (video discarded) |
Cookbook
Worked scenarios for matching a platform's audio spec. The tool always produces MP3; pick the bitrate that fits the requirement.
WAV master down to 320 kbps MP3 for a distributor
A distributor accepts MP3 at 320 kbps. Drop the WAV master and encode straight to 320 kbps MP3.
Input: master.wav 1411 kbps PCM 3:30 ~37 MB Target: 320 kbps (dropdown: '320 kbps · best') Output: master.mp3 320 kbps CBR 3:30 ~8.4 MB
M4A voice memo to 64 kbps MP3 for a chat app
A phone-recorded M4A needs to become a small MP3 for a chat platform that prefers MP3.
Input: memo.m4a ~96 kbps AAC 2:00 Target: 64 kbps (dropdown: '64 kbps · voice') Output: memo.mp3 64 kbps CBR 2:00 ~0.96 MB
Podcast episode re-encoded to host's 128 kbps
Your editing app exported at 192 kbps but the host wants 128 kbps. Re-encode once to match.
Input: ep12.mp3 192 kbps 38:00 ~52 MB Target: 128 kbps (dropdown: '128 kbps · podcast') Output: ep12.mp3 128 kbps 38:00 ~35 MB
Pull a video's audio and set the bitrate
Drop a video file; the audio track is decoded and re-encoded to MP3 while the video is discarded.
Input: talk.mp4 (audio track) 12:00 Target: 128 kbps Output: talk.mp3 128 kbps 12:00 ~11 MB Note: for a dedicated path use [video-to-mp3](/audio-tools/video-to-mp3)
When the spec needs VBR — use a different path
If a platform mandates VBR specifically, this tool cannot satisfy it because it only writes CBR.
Spec: 'MP3, VBR ~V2 (~190 kbps)' This tool: CBR only -> cannot produce VBR Closest CBR match here: 192 kbps · default (Verify the platform accepts CBR before relying on this)
Edge cases and what actually happens
Platform requires a non-MP3 format
Not supported hereThis tool always outputs MP3. For WAV, FLAC, or M4A delivery use a dedicated converter such as sample-rate-converter (WAV) or the format-specific converters; the bitrate changer has no format selector.
Requested bitrate not in the list
By designOnly 320, 256, 192, 128, and 64 kbps are offered. If a spec asks for 96 or 160 kbps, pick the nearest available value and confirm the platform accepts it.
Platform mandates VBR
Not supportedThe tool encodes constant bitrate only. There is no VBR mode, so a strict VBR requirement cannot be met here.
Lossless source down to a low bitrate
ExpectedEncoding a WAV/FLAC to 64–128 kbps MP3 is a large lossy step. Fine for delivery, but keep the lossless master for archival; you cannot regenerate it from the MP3.
Input exceeds 50 MB (free)
Tier limitFree tier caps input at 50 MB and 30 minutes. A long WAV easily exceeds this. Trim first, or upgrade for 200 MB / 120 min.
Video file with no audio track
ErrorIf the dropped video contains no audio stream, there is nothing to encode and the job fails. Use a source that actually has audio.
Tags lost in transit
PreservedTags and cover art are copied via -map_metadata 0. If the source had no tags, the output has none — nothing was stripped.
Bitrate set higher than source
By designRe-encoding up does not improve audible quality; it only enlarges the file. Match or reduce the bitrate for real benefit.
Processing is slow on a long file
ExpectedAll work is local CPU. Long durations take longer to re-encode. Pro builds can use multi-threaded FFmpeg when the browser allows cross-origin isolation.
Frequently asked questions
What formats can I drop in?
MP3, WAV, FLAC, M4A, OGG, Opus, or a video file (its audio track). All of them are re-encoded to MP3 at your chosen bitrate.
What format do I get out?
Always MP3. This tool has no output-format selector; for other containers use a dedicated converter.
Is it really free with no account?
Yes. The free tier needs no account and runs entirely in the browser, up to 50 MB and 30 minutes per file.
Does my audio get uploaded?
No. FFmpeg 8.1 runs as WebAssembly in your tab, so the file is processed locally and never uploaded.
Which bitrates are available?
320, 256, 192 (default), 128, and 64 kbps, all constant bitrate.
Can I produce VBR output?
No. The tool only writes CBR. If a platform strictly requires VBR, this tool will not satisfy it.
How do I match a spec like '96 kbps'?
96 kbps is not one of the five targets. Pick the nearest value (128 or 64 kbps) and confirm the platform accepts it.
Will increasing bitrate fix a poor-quality source?
No. A higher bitrate on a low-quality source only makes a bigger file; lost detail cannot be restored.
Are my tags and cover art kept?
Yes, ID3 tags and embedded artwork are carried into the new MP3.
What is the size and duration limit?
Free: 50 MB / 30 min / 1 file. Pro: 200 MB / 120 min / 10 files. Pro-media and Developer go up to 100 GB with no duration cap.
Can I extract audio from a video here?
Yes, the audio track is used. For a purpose-built workflow with more options, use video-to-mp3.
Does changing bitrate alter pitch or speed?
No. Bitrate is independent of pitch, tempo, and duration; only the data rate changes.
Privacy first
Every JAD Audio tool runs entirely in your browser via FFmpeg (WebAssembly) and RNNoise. Your audio files never leave your device — verified by zero outbound network requests during processing.