How to convert flac to mp3 — free, browser-based, no upload
- Step 1Open the FLAC to MP3 converter — Load the flac-to-mp3 tool. The FFmpeg WebAssembly engine initialises in the tab on first use; nothing is sent to a server.
- Step 2Drop your FLAC file — Drag a single
.flacfile onto the drop zone (or click to browse). The converter takes one file per run — for a whole folder, queue them one at a time. The panel shows the file size and detected duration once it loads. - Step 3Pick a bitrate — Choose from the Bitrate dropdown:
320k(best),256k,192k(default),128k(podcast-grade), or64k(voice). This is the only setting for this tool — there is no VBR, sample-rate, or channel control here. Higher bitrate means larger file and closer-to-lossless sound. - Step 4Run the conversion — Click run. FFmpeg decodes the FLAC to PCM and re-encodes to MP3 with LAME at your chosen CBR target. A 4-minute track typically finishes in a few seconds on a modern laptop.
- Step 5Download the MP3 — The output keeps the original base filename with a
.mp3extension. ID3 tags and embedded artwork are already attached — no follow-up tagging step needed for standard fields. - Step 6Keep the FLAC original — FLAC to MP3 is a one-way lossy conversion — you cannot recover lossless quality from the MP3 later. Archive the FLAC and treat the MP3 as a working/playback copy. To go the other direction for archiving, use mp3-to-flac or wav-to-flac.
Bitrate dropdown — what each option is for
The exact options exposed by the converter UI. All are constant-bitrate (CBR) MP3, applied via FFmpeg's -b:a flag with the LAME encoder. Default is 192k.
| Bitrate | Label in UI | Approx size per minute | Best for |
|---|---|---|---|
320k | 320 kbps · best | ~2.4 MB/min | Critical listening, keeping closest to the FLAC on good headphones or a hi-fi |
256k | 256 kbps | ~1.9 MB/min | High-quality music with a modest size saving over 320k |
192k | 192 kbps · default | ~1.4 MB/min | The all-round default — transparent for most listeners on most gear |
128k | 128 kbps · podcast | ~0.9 MB/min | Spoken word, podcasts, audiobooks, or where size matters more than fidelity |
64k | 64 kbps · voice | ~0.5 MB/min | Pure voice / dictation where intelligibility is all that matters |
What is preserved vs changed in the conversion
Grounded in the converter's FFmpeg argument list. The converter does not resample, downmix, or re-tag beyond carrying the source metadata.
| Property | Behaviour | Why |
|---|---|---|
| Codec | FLAC (lossless) → MP3 (lossy, LAME) | -c:a libmp3lame re-encodes the decoded PCM |
| Sample rate | Preserved from source (e.g. 44.1 / 48 / 96 kHz) | No -ar is passed for this tool |
| Channels | Preserved from source (mono / stereo) | No -ac is passed — no downmix |
| ID3 / Vorbis tags | Carried across to ID3v2.3 | -map_metadata 0 then -id3v2_version 3 |
| Embedded cover art | Re-attached if present | -map 0:v? -c:v copy -disposition:v:0 attached_pic |
| Bitrate | Your chosen CBR target (default 192k) | -b:a <choice> |
Cookbook
Real conversion scenarios with the FFmpeg-equivalent of what the tool runs under the hood. The tool builds these arguments for you — the commands are shown so you can see exactly what happens to your file.
Single Bandcamp FLAC download to a 320k MP3
You bought an album as FLAC and want a phone-friendly MP3 at top quality. Pick 320k. The cover art and tags ride along automatically.
Input: Artist - Track 01.flac (44.1 kHz / stereo / 28 MB)
Setting: Bitrate = 320k
Equivalent FFmpeg:
ffmpeg -i input.flac -c:a libmp3lame -b:a 320k \
-map_metadata 0 -map 0:a -map 0:v? -c:v copy \
-disposition:v:0 attached_pic -id3v2_version 3 out.mp3
Output: Artist - Track 01.mp3 (44.1 kHz / stereo / ~5.6 MB)
Title/Artist/Album tags + cover art preserved.192k default for a general music library
Leaving the default alone is the right call for most music libraries — 192k CBR is transparent on most equipment and roughly a quarter the size of the FLAC.
Input: song.flac (48 kHz / stereo / 32 MB) Setting: Bitrate = 192k (default — no change needed) Output: song.mp3 (48 kHz / stereo / ~5.8 MB for 4:10) Sample rate stays 48 kHz (no resample); stereo preserved.
High-res 96 kHz FLAC stays 96 kHz
The converter does not resample. A 96 kHz hi-res FLAC produces a 96 kHz MP3. If you specifically want 44.1 kHz for an old player, convert here first then resample with the dedicated tool.
Input: hires.flac (96 kHz / stereo / 24-bit) Setting: Bitrate = 256k Output: hires.mp3 (96 kHz / stereo) Need 44.1 kHz too? Follow up with sample-rate-converter (this tool has no sample-rate control of its own).
Voice-only FLAC to a tiny 64k file
A spoken-word FLAC (interview, dictation) does not need music bitrates. 64k keeps it intelligible at roughly a tenth of the 192k size.
Input: interview.flac (44.1 kHz / mono / 60 MB, 70 min) Setting: Bitrate = 64k Output: interview.mp3 (44.1 kHz / mono / ~33 MB) Note: 70 min / 60 MB exceeds the Free tier (30 min / 50 MB) — this run needs Pro (120 min / 200 MB).
Album side as one file, then split later
If your FLAC is a continuous album side, convert the whole thing to one MP3 first, then split. The converter does not split — that is a separate tool.
Input: side-a.flac (44.1 kHz / stereo / 22 min) Setting: Bitrate = 320k Output: side-a.mp3 (one continuous file) To cut it into tracks afterward, use audio-splitter (/audio-tools/audio-splitter).
Edge cases and what actually happens
File over the Free tier 50 MB / 30 min limit
Blocked on FreeA FLAC can be large — lossless 44.1 kHz stereo is roughly 5-10 MB per minute, so a full album easily passes 50 MB or 30 minutes. On Free the run is blocked. Pro raises this to 200 MB / 120 minutes / 10 files; Pro-media and Developer to 100 GB with unlimited duration. The limit is on the input file's size and duration, not the MP3 output.
Expecting VBR (V0/V2) output
By designThis converter exposes only CBR targets via -b:a — there is no VBR (LAME -V) mode in the UI. If you need VBR specifically, that control is not available here; pick the nearest CBR (320k ≈ V0-grade, 192k ≈ V2-grade in practical size/quality terms) and accept a fixed bitrate.
Wanting to downsample to 44.1 kHz during conversion
Not in this toolSample rate is preserved, not changed — a 96 kHz FLAC yields a 96 kHz MP3. There is no sample-rate control on this page. Convert here, then run the result through sample-rate-converter if you need 44.1 kHz for an old device.
FLAC has no embedded cover art
ExpectedThe cover-copy step uses -map 0:v? — the ? makes the video/cover stream optional. If the FLAC has no embedded picture, the conversion proceeds normally and the MP3 simply has no artwork. To add art afterward, use id3-editor.
Tags use Vorbis comments, not ID3
PreservedFLAC stores metadata as Vorbis comments. FFmpeg's -map_metadata 0 maps recognised fields to their ID3 equivalents in the MP3 (title, artist, album, date, track). Non-standard custom Vorbis fields may not have an ID3 counterpart and can be dropped — re-add anything critical with id3-editor.
Trying to drop multiple FLACs at once
One per runThe converter processes one file per run (acceptsMultiple: false). Drop the next file after the first finishes. Batch counts only matter for tools that accept multiple inputs; here, convert sequentially.
Corrupt or truncated FLAC
Decode errorIf the FLAC header is damaged or the file is truncated mid-stream, FFmpeg's decoder errors out and the run fails rather than producing a partial MP3. Re-download or re-rip the source FLAC. A FLAC that plays fine in a media player will decode fine here.
Input is actually a .flac container with non-FLAC data
Format mismatchA file renamed to .flac that is not actually FLAC (e.g. a renamed WAV or ALAC) may fail to decode or be misdetected. FFmpeg probes the real stream, so use the matching tool — wav-to-mp3 for WAV, or m4a-to-mp3 for ALAC/AAC in an M4A.
Expecting the MP3 to sound identical to the FLAC
Lossy by natureMP3 is lossy — even 320k discards data the FLAC kept. For most listeners on most gear the difference is inaudible, but it is not bit-identical. Keep the FLAC as your master; the MP3 is a portable copy.
Frequently asked questions
Is this FLAC to MP3 converter really free with no upload?
Yes. The conversion runs in your browser via FFmpeg 8.1 compiled to WebAssembly — your FLAC is decoded and re-encoded on your own device and is never sent to a server. There is no account requirement to convert a single file within the Free tier's 50 MB / 30-minute limit, and there is no watermark on the output.
What MP3 encoder does it use?
LAME, via FFmpeg's libmp3lame. It is the de-facto standard MP3 encoder and is what gives high-quality MP3 at any target bitrate. The conversion writes constant-bitrate (CBR) MP3 at the bitrate you select.
What bitrates can I choose?
The dropdown offers 320k (best), 256k, 192k (the default), 128k (podcast-grade), and 64k (voice). They are all CBR. There is no VBR option in this tool — if you specifically need V0/V2, this page does not expose it.
Does it keep album art and tags?
Yes. The converter passes -map_metadata 0 to carry title/artist/album/year/track across, re-attaches any embedded cover art with a stream copy, and writes ID3v2.3. Standard fields and artwork survive automatically. Custom non-standard Vorbis comment fields may not map and can be re-added with the id3-editor tool.
Will it change my sample rate or downmix to mono?
No. The converter preserves the source sample rate and channel layout — it does not pass -ar or -ac for this tool. A 96 kHz stereo FLAC produces a 96 kHz stereo MP3. To resample, use the sample-rate-converter tool after conversion.
What's the best bitrate to pick?
For music on good gear, 320k stays closest to the FLAC; 192k (the default) is transparent for most people and about a quarter the size. For podcasts/audiobooks, 128k is plenty; for pure voice, 64k. There is no single right answer — it is a size-versus-fidelity trade.
How big will the MP3 be?
Roughly bitrate × duration. As a rule of thumb: 320k ≈ 2.4 MB/min, 192k ≈ 1.4 MB/min, 128k ≈ 0.9 MB/min, 64k ≈ 0.5 MB/min. So a 4-minute track at 192k is about 5.6 MB — versus 20-40 MB as FLAC.
Can I convert a whole album folder at once?
This converter takes one file per run. Convert each track in turn, or queue them. If you need to merge an album side into one file first, use audio-merger; to split one continuous file into tracks afterward, use audio-splitter.
Why is my large FLAC blocked?
The Free tier caps input at 50 MB and 30 minutes per file. Lossless FLAC is big, so full albums often exceed this. Pro raises it to 200 MB / 120 minutes / 10 files, and Pro-media/Developer to 100 GB with unlimited duration.
Can I get the FLAC quality back from the MP3 later?
No — MP3 conversion is lossy and one-way. The discarded data is gone. Always keep the original FLAC as your archive; converting it to MP3 with mp3-to-flac afterward would only wrap the lossy MP3 audio in a FLAC container, not restore quality.
Does it work offline?
After the FFmpeg WebAssembly engine has loaded once in the tab, the actual conversion is local and does not need an ongoing upload connection. The initial page and engine load do require fetching the assets, but no audio data is transmitted at any point.
What's the difference between this and the bitrate-changer?
This tool specifically decodes FLAC and outputs MP3. The bitrate-changer re-encodes an existing audio file to a new bitrate (and can target several formats). For FLAC-to-MP3, this dedicated converter is the right choice; use bitrate-changer when you already have an MP3 and want it at a different bitrate.
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.