MP3 FLAC

MP3 to FLAC Converter

Convert MP3 to FLAC in your browser. Free, private, and fast. Choose the right codec, quality, and file size without sending files to a server.

This converter runs a full FFmpeg engine in your browser. The first conversion downloads the engine (~31 MB, cached afterwards) — your file itself still never leaves your device.

Drag & drop your MP3 file here

or

Max file size: 50 MB · Your file stays in your browser

Your file is processed locally in your browser — nothing is ever uploaded.

Why Convert MP3 to FLAC?

Converting MP3 to FLAC is a common task whenever a file has to work somewhere that expects the other format. MP3 is the world's most widely supported audio format. FLAC compresses audio without losing any information: a FLAC file decodes to a bit-identical copy of the original recording while typically being 40–60% smaller than WAV. This converter makes the switch locally in your browser — nothing is uploaded.

Common use cases

  • You have a MP3 file and need it in FLAC format.
  • The target software or platform requires FLAC but your file is in MP3.
  • Typical use of FLAC: Archiving CD rips and studio recordings without quality loss.
  • You want to reduce file size or improve compatibility without using desktop software.
Keep in mind: FLAC files are still several times larger than MP3 or M4A, and not every phone, car stereo or older player can play them.

How to Convert MP3 to FLAC

  1. Upload or drop your MP3 file into the converter above.
  2. Adjust any output settings for FLAC if needed.
  3. Click Convert and download your converted file instantly.

About the Formats

MP3 (MPEG Audio Layer III)

MP3 is the world's most widely supported audio format. Introduced in 1993, it uses psychoacoustic compression to dramatically reduce file sizes while preserving perceptible audio quality.

Compatibility: Universal — supported by every device, browser, media player, and platform.

FLAC (Free Lossless Audio Codec)

FLAC compresses audio without losing any information: a FLAC file decodes to a bit-identical copy of the original recording while typically being 40–60% smaller than WAV. It is the preferred format for music archives, audiophile libraries and lossless downloads.

Compatibility: Plays natively in Chrome, Firefox, Edge, Safari 11+, Android and iOS 11+; most hi-fi players and music software support it.

100% Private & Browser-Based

Your files never leave your device. All conversion happens locally in your browser — nothing is uploaded to any server. No sign-up required.

MP3 to M4A Converter MP3 to OGG Converter MP3 to WAV Converter MP3 to OPUS Converter MP3 to WMA Converter MP3 to AAC Converter
WAV to FLAC Converter OGG to FLAC Converter M4A to FLAC Converter

Need the reverse?

FLAC to MP3 Converter

FAQ

Frequently Asked Questions

Yes — completely free with no sign-up, no watermarks, and no size limits for typical files.

Quality depends on the output settings. For lossless output, choose the highest quality setting available.

Your file is processed entirely within your browser using local JavaScript. It is never uploaded to any server. Only you can access your file.

For browser-based conversion, files up to 50 MB work best. Very large files may take longer depending on your device. We recommend splitting very large files before converting.

Currently, AintoB converts one file at a time to keep the browser-based process simple and private. Reload the page to convert another file.