FLAC Converter, Convert Audio to Lossless FLAC Online, In Your Browser
Drop a WAV, MP3, M4A, AAC or OGG file and get a lossless FLAC: bit-perfect audio at a fraction of a WAV's size. Native decode, on-device ffmpeg encode, a waveform preview and an exact before/after size readout. Never uploaded.
What is the flac converter?
The FLAC Converter encodes audio to FLAC, the Free Lossless Audio Codec that preserves every sample bit-for-bit yet runs roughly 40–60% smaller than uncompressed WAV. Drop WAV, MP3, M4A, AAC or OGG and an on-device ffmpeg engine writes a standard, universally-readable .flac with a waveform preview and exact size readout. Ideal for archiving. Nothing is uploaded.
The GigAI FLAC Converter turns almost any audio your browser can decode into FLAC (the Free Lossless Audio Codec) without your file ever touching a server. FLAC is the format archivists, audiophiles and mastering engineers reach for because it stores audio losslessly: every sample is preserved exactly, yet the file is typically 40–60% smaller than the equivalent uncompressed WAV. This converter decodes your source natively with the Web Audio API, hands the resulting bit-exact audio to an on-device ffmpeg engine, and writes a standard.flac file you can download in one click. Because FLAC is lossless, converting from a WAV, AIFF or another lossless master gives you a genuinely perfect, compressed copy, ideal for a music library, a backup, or delivering a master that a lossy MP3 would degrade. It's equally happy to package a lossy source: converting an MP3 or M4A to FLAC won't magically restore the detail those codecs discarded, but it gives you a lossless container that many hi-fi players, DAWs and streaming pipelines specifically require, and it won't lose anything further no matter how many times you re-open it. The workspace shows the source waveform, duration, sample rate and channels the instant you drop a file, encodes with a live progress bar, and then reports the exact original and FLAC byte sizes so you can see precisely how much smaller (from a WAV) (or larger (from an MP3)) the lossless version is before you commit. The ffmpeg core loads only when you actually convert, once per session, and everything runs in the tab: interviews, unreleased tracks and confidential recordings never leave your device. Close the tab and every byte is gone.
- Difficulty:
- Medium
- Typical time:
- ~30s
- Processing:
- 100% browser processing
Last updated
How to use the flac converter
- 1
Drop your audio
Drag a WAV, MP3, M4A, AAC, OGG or other decodable file onto the workspace, or click to browse. It's read locally and you'll see its waveform, duration, sample rate and channels immediately.
- 2
Preview the source
Play back the waveform to confirm it's the right file and check the readout: a lossless source (WAV/AIFF) gives a truly perfect FLAC, a lossy one (MP3/M4A) gives a lossless container of already-compressed audio.
- 3
Convert
Press Convert to FLAC. The on-device ffmpeg core loads once the first time, then a progress bar tracks the lossless encode locally: nothing is uploaded at any point.
- 4
Check the size & download
Read the original vs FLAC size to see exactly how much smaller (from a WAV) or larger (from an MP3) the lossless file is, then download your.flac, or reset and drop another file.
What FLAC Converter includes
Convert almost anything to FLAC
Drop WAV, MP3, M4A, AAC, OGG, WEBM or the audio out of most containers. If your browser can decode it, this writes a standard, universally-readable.flac. No format lookup, no guessing.
Truly lossless encoding
FLAC preserves every sample exactly. No quality is discarded during compression. Convert a WAV or AIFF master and the FLAC is bit-for-bit identical audio, just packed into a much smaller file.
Smaller than WAV, zero quality loss
A FLAC is typically 40–60% smaller than the same uncompressed WAV while sounding identical. Archive a whole library or back up masters at roughly half the disk cost with nothing thrown away.
Waveform preview before you commit
See the source waveform plus its duration, sample rate and channels the moment you drop it, so you're converting the right file at the right resolution. Not encoding blind.
Exact before / after size
When it finishes you get the original bytes and the FLAC bytes side by side (the real shrink from a WAV, or the honest growth from a lossy source) not a vague 'optimized' badge.
100% private, nothing uploaded
Decoding and encoding both happen on your device. Interviews, voice memos and unreleased tracks are never uploaded, stored or logged, there's no upload bar and no cloud copy.
Why use our flac converter
Perfect quality at half the size
FLAC gives you every bit of a WAV master in a file that's usually 40–60% smaller. It's the format of choice for music libraries, backups and delivery when 'lossless but not huge' is the goal.
The format hi-fi and studios ask for
Audiophile players, mastering pipelines, distribution platforms and many DAWs specifically want FLAC for lossless delivery. Convert once and hand over exactly the file they expect.
No upload wait, no privacy tradeoff
Server converters make you upload first and trust them with the file. Here the audio never leaves your browser, so there's no upload bar and nothing to trust with a private recording or unreleased track.
A container that never degrades again
Even from a lossy source, wrapping audio in FLAC means it won't lose anything further, re-open, re-copy and re-embed it as many times as you like with no generational quality drift.
Built for the way you work
From quick one-off fixes to daily workflows, see how people put this tool to use.
- Audiophile / Collector
Rip and archive a library in lossless FLAC
You want a music collection that's bit-perfect but not the disk-hog WAV is. Convert your WAV rips to FLAC and store every track losslessly at roughly half the size, ready for any hi-fi player.
- Musician / Mastering engineer
Deliver a lossless master without the WAV bulk
A client or distributor asks for lossless, but a full WAV is unwieldy to send. Encode the master to FLAC for a bit-identical delivery file that's far lighter to upload and store.
- Podcaster / Archivist
Preserve a recording in a future-proof format
For long-term archival you want a lossless, open, widely-supported container. Convert your source to FLAC so the original quality is preserved exactly and the file opens decades from now.
- Privacy-conscious user
Convert a private recording locally
An interview, a medical note or a confidential voice memo shouldn't be uploaded to a stranger's converter. Encode it to FLAC entirely in your browser so the audio never leaves the device.
Supported formats
Accepts WAV, MP3, M4A, AAC and OGG, and produces FLAC, all processed locally in your browser.
- WAV
- MP3
- M4A
- AAC
- OGG
- WEBM
- FLAC
- FLAC
Frequently asked questions
Recommended tools
MP3 Converter
Convert any audio to MP3 in your browser, WAV, M4A, AAC, OGG, FLAC and more to a clean, universally-playable MP3 with a bitrate you choose. Preview the waveform, encode locally with lamejs, then download. Nothing is uploaded.
Audio Trimmer
Trim audio in your browser with a real waveform: drop an MP3, WAV, M4A or OGG, drag a selection to keep exactly the part you want, preview it, then download a lossless WAV or a compact MP3. Sample-accurate and 100% private. Nothing is uploaded.
Audio Normalizer
Normalize audio volume in your browser: lift a too-quiet recording to a clean target level with peak or RMS normalisation, compare the before/after waveform, then download WAV or MP3. Nothing is uploaded.
Audio Recorder
Record from your microphone right in the browser: live level meter and timer, trim the ends on a waveform, then export a clean WAV or MP3. Nothing is uploaded. Your audio never leaves your device.
AAC Converter
Convert any audio to AAC in your browser, WAV, MP3, M4A, OGG, FLAC and more to a compact, high-efficiency.aac file that plays natively on iPhone, Android, YouTube and modern video apps. Preview the waveform, encode locally, then download. Nothing is uploaded.
M4A Converter
Convert any audio to M4A (AAC) in your browser, WAV, MP3, OGG, FLAC and more into a clean, Apple-friendly.m4a that plays perfectly on iPhone, iPad, Mac and iTunes. Preview the waveform, choose AAC or M4A output, then download. Nothing is uploaded.
Comparisons & guides
Go deeper on the concepts behind the flac converter.
Common problems, solved
Hit a snag? Here are quick fixes for the issues people run into most.
My FLAC is bigger than the MP3 I started with.
That's expected. FLAC is lossless, so it can't compress as aggressively as a lossy MP3, and it can only store the (already-reduced) audio the MP3 contained. Converting MP3 → FLAC gives you a lossless container, not smaller files or restored quality. Convert from a WAV or AIFF if your goal is a smaller-than-WAV lossless archive.
The file wouldn't load or decode.
The converter can only handle audio your browser can decode. Most WAV, MP3, M4A/AAC and OGG files work. A DRM-protected purchase, a raw/exotic codec or a corrupt file may not. Try re-exporting the source to WAV first, then convert that to FLAC.
Conversion paused while an engine loaded.
FLAC encoding uses an on-device ffmpeg core (~31 MB) that downloads once the first time you convert, then stays cached for the session. Subsequent conversions skip the wait. The core runs locally. Nothing about your audio is uploaded during or after the load.
The tab got slow or ran out of memory on a very long file.
Lossless encoding holds the decoded audio in memory, so a multi-hour, high-sample-rate recording on a low-memory device can strain the tab. Close other heavy tabs and try again. For the longest files, trim the audio first (see the Audio Trimmer) or convert in shorter sections.
Get the most out of it
Convert from a lossless source (WAV, AIFF or an existing FLAC) whenever you can: that's the only way the FLAC is genuinely bit-perfect audio.
Expect a FLAC to be roughly 40–60% the size of the same WAV. The busier and noisier the audio, the less it compresses, so acoustic and spoken material shrinks most.
Converting MP3 or M4A to FLAC is useful when a player or pipeline demands a lossless container, but it won't restore detail, and the FLAC will usually be larger than the MP3.
The ffmpeg core loads once per session on your first conversion. After that every FLAC encode is download-free for the rest of the session.
Watch the before/after size readout, from a WAV it confirms the space you saved, from a lossy source it warns you the file grew.
What's new
Recent updates and improvements to the flac converter.
Initial release: in-browser FLAC conversion via an on-device ffmpeg core, native Web Audio decoding, a source waveform preview, an exact before/after size readout and one-click download.
Added clearer engine-loading state so the one-time ~31 MB core download is obvious, plus an honest lossless/lossy-source note that warns when a FLAC will be larger than a lossy input.
Improved memory handling on long, high-sample-rate files and added drag-and-drop plus reset so you can convert file after file without reloading the page.
Keep exploring
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Your privacy is built in
Your audio is decoded natively with the Web Audio API and encoded to FLAC by an on-device ffmpeg core that runs entirely in your browser. Nothing is ever uploaded to a server, stored or logged: the ~31 MB core downloads once per session purely so the encode can run locally, and no audio data leaves the tab during or after that load. You can safely convert interviews, voice memos and unreleased tracks. There's no upload step and no cloud copy, and closing the tab discards every byte.
- Runs in your browser
- No uploads
- Nothing stored
Ready to try the flac converter?
Free, private and instant. FLAC Converter runs right in your browser.