Is my FLAC file uploaded to a server?

No. FFmpeg is compiled to WebAssembly and runs entirely inside your browser. Your file is loaded into browser memory only and is never transmitted to any server.

Does converting FLAC to OGG lose quality?

Yes. OGG Vorbis is a lossy format, so some audio data is discarded during encoding. At the default quality level (q:a 4, roughly 128–160 kbps variable bitrate), most listeners cannot distinguish the result from the original FLAC on normal playback systems. Keep the original FLAC if archival quality matters.

What is OGG Vorbis and why use it?

OGG Vorbis is an open, royalty-free lossy audio codec. Unlike MP3, it is free of software patents, making it the preferred format for open-source games, Linux applications, and web platforms that avoid proprietary formats.

Why does loading take a few seconds the first time?

FFmpeg.wasm is a roughly 10 MB WebAssembly binary that must be downloaded and compiled by your browser before conversion can begin. This happens once per page visit. Subsequent conversions on the same page are instant.

What quality setting does the converter use?

The tool uses FFmpeg's libvorbis encoder at quality level 4 (the default), which targets around 128–160 kbps variable bitrate. This provides a good balance between file size and audio fidelity for most use cases.

What browsers are supported?

A modern browser with WebAssembly support is required. This tool loads the single-thread @ffmpeg/core build, so SharedArrayBuffer and cross-origin isolation are not required. The page will show an error if the required APIs or converter resources cannot load.

FLAC to OGG Audio Converter

Drop a FLAC file and download an OGG Vorbis copy — FFmpeg runs entirely in your browser, nothing is uploaded.

Select FLAC File

Drop FLAC here or click to browse Supports .flac files

FFmpeg runs locally in your browser — first load may take a few seconds.

FLAC vs. OGG Vorbis

FLAC — lossless, large files (20–40 MB/track), perfect for archival

OGG Vorbis — lossy, small files (~5–8 MB/track), open & patent-free

Output quality: ~128–160 kbps VBR (transparent for most listeners)

Converted OGG file will appear here

Done!

Summary

FLAC is a lossless audio format that preserves every bit of the original recording, but its large file sizes are impractical for web games, portable devices, or sharing. OGG Vorbis is an open, royalty-free codec that offers excellent quality at much smaller file sizes. This tool transcodes your FLAC to OGG Vorbis directly in the browser using FFmpeg compiled to WebAssembly — your file is never sent to any server. The conversion preserves the original sample rate and channel layout while re-encoding to OGG at a high-quality variable bitrate.

How it works

Click the upload area or drag a FLAC file onto it.
FFmpeg.wasm loads in the background (one-time download, ~10 MB).
Click "Convert to OGG" — FFmpeg runs inside a browser Web Worker.
The transcoded OGG file is written to browser memory.
A download button appears — click it to save the OGG file locally.
Your audio data never leaves your device at any point.

Use cases

Prepare FLAC audio assets for HTML5 web games that require OGG format.
Compress a large FLAC music library for portable devices with limited storage.
Convert FLAC recordings for use in game engines such as Godot or Pygame.
Archive FLAC masters while distributing smaller OGG copies for streaming.
Produce OGG files for Wikipedia or other open-content platforms.
Convert FLAC podcast recordings to a web-friendly open format.
Reduce file size for web embedding while avoiding proprietary codec licenses.
Provide OGG fallback audio alongside MP3 for browser compatibility.

Frequently Asked Questions

Last updated: 2026-05-29 · Reviewed by Nham Vu