Is this FLAC to AAC converter really free?

Yes. Up to 5 files at a time, no signup, no catch. The free tier adds a small watermark to image output — Pro ($9.99/mo or $49/yr) removes it, raises the file size limit to 500 MB, and unlocks unlimited batch conversion.

Are my files uploaded to a server?

No — and you can verify it yourself. Open DevTools → Network tab, then convert a file. You'll see zero upload requests. Everything runs right in your browser. We never see your files.

How long does conversion take?

Usually 1–3 seconds for a typical file. The very first conversion on a fresh page load may take 5–20 seconds while the converter engine loads — after that it's instant. Your CPU does all the work locally.

What is the file size limit?

Free: up to 10 MB per file, 5 files per batch. Pro: up to 500 MB per file, unlimited batch. If you're working with large videos or RAW photos, Pro is built for that.

Can I batch convert multiple FLAC files at once?

Yes — drop multiple files at once (or Ctrl/Cmd+click to select them) and they all convert in parallel. Free accounts handle up to 5 files per batch; Pro has no limit.

What bitrate will the converted audio use?

We default to 192 kbps for MP3, 128 kbps for OGG/Opus, and 320 kbps for M4A/AAC. These settings are perceptually transparent — most listeners can't tell the difference in a blind test.

Will my metadata (ID3 tags, album art) be preserved?

Yes, when both formats support it. Tags carry over on conversions like MP3→M4A or FLAC→MP3. WAV has limited tag support, so some metadata may not transfer.

What bitrate should I choose when converting FLAC to AAC?

For music, 192–256 kbps AAC is recommended for transparent quality. For podcasts or voice content, 96–128 kbps is sufficient. Higher bitrates produce larger files with diminishing returns.

Is AAC or M4A — what's the extension difference?

AAC (.aac) is the raw codec bitstream; M4A (.m4a) is the same codec wrapped in an MP4 container. Most players accept both. Apple devices and iTunes work with M4A; broadcast systems sometimes require raw .aac.

How private is this converter?

Completely private — by design, not policy. There is no upload endpoint. Files are processed right inside your browser tab and disappear the moment you close it. We collect only anonymous page-view counts; your file content is never seen or stored.

FLAC to AAC Converter — Free, Online, No Upload

How to convert FLAC to AAC online

1
Drop your FLAC file
Drag and drop your Free Lossless Audio Codec file onto the converter, or click to browse your files. You can select up to 5 at once. Nothing leaves your device — conversion happens right here in the browser.
2
Hit Convert — it happens locally
Click Convert and watch it go. There's no upload, no server queue, no waiting. The converter runs Free Lossless Audio Codec → Advanced Audio Coding entirely in your browser tab. Most files finish in 1–3 seconds.
3
Download your AAC
Your Advanced Audio Coding file is ready. Click Download, or grab a ZIP if you converted a batch. Close the tab and everything disappears — no copies kept anywhere.

FLAC vs AAC: format overview

FLAC

Free Lossless Audio Codec

Josh Coalson / Xiph.Org · 2001

Compression: lossless
Transparency: No

✓ Lossless compression — identical to source
✓ 50–60% smaller than WAV with no quality loss
✗ Not supported on iOS/iTunes natively

AAC

Advanced Audio Coding

Dolby, Fraunhofer, Sony, Nokia · 1997

Compression: lossy
Transparency: No

✓ Successor to MP3 — better quality at same bitrate
✓ Native support across Apple, Android, YouTube

FLAC magic bytes: 66 4C 61 43

AAC magic bytes: FF F1 (ADTS) / 00 00 00 xx 66 74 79 70

Why convert FLAC to AAC?

FLAC is unbeatable for archiving and audiophile hardware, but it's not a distribution format. Streaming platforms, podcast hosts, broadcast delivery systems, smart TVs, and most consumer devices outside the Linux and audiophile world expect AAC or MP3. AAC is the more modern of the two — it achieves better quality at the same bitrate, and it's the codec used internally by Apple Music, Spotify, YouTube, and virtually every streaming platform.

Converting from FLAC to AAC is the standard step for anyone preparing audio for broad distribution. Apple Podcasts requires AAC or MP3; uploading AAC directly is accepted and often preferred. Spotify converts uploads to its internal streaming format, but AAC or MP3 uploads are the standard input. YouTube encodes uploaded audio to AAC for delivery. Smart TVs and home theatre receivers that can't read FLAC natively play AAC without issues. Android handles AAC natively across all versions.

Because FLAC is lossless, you're starting from the cleanest possible source for the AAC encode — there's no prior generation loss stacking up. At 192–256 kbps, the AAC output will be indistinguishable from the FLAC source in any reasonable listening environment. The file will be roughly 85–90% smaller than the FLAC. AAC (.aac) differs from M4A (.m4a) only in the container — both use the same codec; choose M4A if your destination is iTunes or Apple devices.

Quality & file size: FLAC to AAC

Typical file sizes: FLAC 20–40 MB → AAC 2–5 MB.

Converting from lossless FLAC to lossy AAC will apply compression. We default to 85% quality — visually indistinguishable from the original for most content. If you need pixel-perfect output, consider using a lossless target format instead.

Color depth: FLAC supports standard color, AAC supports standard color.

Transparency: FLAC does not support transparency. AAC does not support transparency — transparent areas become solid white.

Frequently asked questions

Privacy: how FormatDrop handles your files

Your FLACfiles are converted 100% inside your browser. They are never uploaded to our servers, never stored, and never seen by anyone other than you. This isn't a privacy policy claim — it's an architectural guarantee: our server has no endpoint that receives file bytes.