Free bulk audio converter
Batch convert FLAC to MP3
Add a whole album folder, convert up to 40 FLAC files in a single run at one shared bitrate, and download the finished MP3s as one ZIP. Every track keeps its own tags and cover art — and nothing is uploaded, so there is no file-size limit and no queue to wait in.
- Up to 40 files per run
- Whole-folder input
- One ZIP download
- No size limit
- Tags kept per track
Everything that is not a .flac file is ignored automatically.
How to batch convert FLAC to MP3
Three steps for a whole album — no software, no upload, one ZIP at the end.
Add the whole folder
Click "Add a whole folder" and pick your album directory — every .flac inside is queued at once and anything else (cue sheets, artwork, logs) is ignored. You can also drag loose files in, up to 40 per batch.
Set one bitrate for the entire batch
Choose 128, 192, 256, or 320 kbps once and it applies to every file in the queue. Files convert one after another so a long batch never exhausts your memory, and switching bitrate mid-run re-converts the whole batch at the new setting.
Download everything as one ZIP
When the queue finishes, one button packages every MP3 into a single archive. Each track keeps its own title, artist, album tags and cover art, so the ZIP drops straight into your music library.
Bulk conversion specifications
| Batch limit | 40 FLAC files per run, added by folder or drag-and-drop |
|---|---|
| Folder input | Directory picker queues every .flac inside; other file types are skipped |
| Output | One MP3 per track at a shared bitrate of 128 / 192 / 256 / 320 kbps |
| Bulk download | Single ZIP archive of the whole batch, with duplicate names numbered |
| Per-file metadata | Tags and cover art copied into ID3v2.3 individually, track order preserved |
| File-size limit | None — no upload means no server-side cap |
| Processing order | Sequential, one file at a time, so memory stays bounded on long queues |
| Speed | About 30× real time — roughly 1–3 minutes for a 12-track album |
| Price | Free — no signup, no watermark, no quota on how many batches you run |
Why bulk conversion works better in the browser
Bulk is where upload-based converters fall apart. A 12-track 16-bit album is around 350 MB of FLAC; a 24-bit rip can pass a gigabyte. Sending that to a server means waiting on your upload speed twice — once up, once back down — and running into the free-tier caps those sites need to stay affordable: a few files per day, 100 MB per file, a watermark or a paid tier for anything larger.
This page never sends a byte. Your browser's built-in FLAC decoder unpacks each track and the LAME MP3 encoder — compiled to JavaScript and running in a background worker — re-encodes it at the bitrate you chose. Files go through the queue one at a time, which keeps memory use flat whether the batch is three files or 40, and the ZIP is assembled locally too.
The practical consequence: the only limits are your own device's. No per-file size cap, no daily quota, no account, and the batch keeps running if your connection drops after the page loads.
Batch conversion FAQ
How many FLAC files can I convert at once?
Up to 40 per batch on this page — double the 20-file limit on the standard converter, which covers a double album or a long compilation. When the queue is done, clear it and add the next 40; there is no daily cap on how many batches you run.
Can I convert an entire album folder at once?
Yes. The "Add a whole folder" button opens a directory picker instead of a file picker, so you select the album folder and every FLAC inside is queued in one click. Non-audio files in the folder — cover.jpg, .cue, .log, .m3u — are filtered out automatically, so you never have to tidy the folder first.
Does the ZIP keep my folder structure?
No — the archive is flat, with one .mp3 per converted track and duplicate names numbered so nothing gets overwritten. Because tags travel with each file, any music player or library manager can rebuild the artist/album folders for you on import.
Is there a file-size limit for bulk conversion?
No. Server-based converters cap uploads because bandwidth costs them money — a 300 MB 24-bit album is exactly what those limits are designed to reject. Here the conversion runs inside your browser, so the only ceiling is your own device's memory. Long live sets and high-resolution rips convert the same as three-minute pop songs.
How long does a bulk conversion take?
Roughly 30 times faster than playback: about 5–15 seconds per 4-minute track, so a 12-track album finishes in one to three minutes and a 40-file batch in about five to ten. Files are processed sequentially and the progress bar shows which one is encoding, so you can leave the tab open and come back.
Can I change the bitrate after the batch has started?
Yes, and it applies retroactively. Picking a different bitrate re-queues every file — including the ones already finished — and converts the whole batch again at the new setting. That makes it easy to compare 192 kbps against 320 kbps on the same album before committing.
Will every MP3 keep its own tags and cover art?
Yes. Each file is tagged individually: title, artist, album, album artist, track and disc number, year, genre, and composer are read from that FLAC's Vorbis comments and written as ID3v2.3 tags, and embedded artwork is carried across. Track numbering therefore survives the batch, so albums stay in order.
Are my files uploaded when I convert in bulk?
No. Nothing is transmitted at any point — decoding, encoding, tagging, and ZIP packaging all happen in your browser tab. You can disconnect from the internet once the page has loaded and the batch will keep converting.
What about converting a library of thousands of files?
Past a few hundred files, a desktop tool that can walk a folder tree unattended is the better fit — fre:ac for a graphical batch queue, or ffmpeg in a shell loop for automation. Our guide to converting FLAC to MP3 covers both, with the exact commands.
Converting something smaller?
For a handful of tracks, the standard FLAC to MP3 converter is the same engine with a simpler queue. If you are weighing this against desktop software for a much bigger job, the guide How to Convert FLAC to MP3 (4 Free Ways) covers fre:ac and the ffmpeg one-liner for converting an entire library unattended.