100% local
AUDIO

Convert ALAC
to OPUS

Significantly smaller files.

ALAC is a lossless format that prioritizes fidelity over size. Converting to OPUS introduces modern compression that typically reduces file size by an order of magnitude with no perceptible difference at normal playback or viewing.

— Drop area

WHY CONVERT

Why convert ALAC to OPUS

01

Significantly smaller files

ALAC is a lossless format that prioritizes fidelity over size. Converting to OPUS introduces modern compression that typically reduces file size by an order of magnitude with no perceptible difference at normal playback or viewing.

02

Broader cross-platform support

OPUS is accepted by a wider range of audio players, car stereos, and streaming services than ALAC. The conversion removes a recurring compatibility friction without changing what the file actually contains.

03

Lower storage and bandwidth cost

OPUS files are typically smaller than their ALAC counterparts, which reduces hosting, transfer, and storage costs at scale. The savings compound when serving the same content to many recipients.

— How to convert

ALAC to OPUS in three steps.

  1. 01

    Open LocalConvert

    Visit this page on any modern browser — no install, no signup, no plugin.

  2. 02

    Drop or select your ALAC file

    Drag your ALAC into the drop area, or click to pick one from your device.

  3. 03

    Click Convert

    Conversion runs entirely in your browser. When it's done, your OPUS file downloads to your device.

QUALITY & FIDELITY

Quality and fidelity

  • Lossless source to lossy target: expect a small, irreversible quality loss.
  • Metadata (EXIF/tags) is preserved where the source provides it.
Transparency ALAC ✗ OPUS ✗
Color depth 16/24-bit lossless audio 16-bit stereo audio
Metadata preserved

FORMAT SPECS

Format specifications

ALACOPUS
Extensions.m4a .caf.opus
MIME typesaudio/alacaudio/opus
Introduced20042012
MaintainerAppleIETF
Magic #
SpecView spec ↗View spec ↗

COMPATIBILITY

Where these formats work

OPUS

Windows
App
macOS
App
iOS
Native
Android
Native
Chrome
Native
Firefox
Native
Safari
Native
Edge
Native

Why LocalConvert

How LocalConvert compares

CategoryLocalConvertCloud converters
PRIVACYFiles never leave your device. The whole pipeline runs in your browser via WebAssembly.Files travel to a remote server, sit in queue storage, and may be retained for analytics or moderation.
COSTFree, no signup, no daily quotas.Often free for small files; paid tiers for batch / large / commercial use.
LIMITSLimited only by your device's memory and CPU. Uncompressed WAV stems handled comfortably on desktop.Typical 100 MB to 1 GB per-file caps, plus rate limits.
— The formats
From · ALAC

Apple Lossless Audio Codec

Apple's lossless audio format inside an M4A container.

Typical uses
Apple Music lossless, iTunes lossless libraries.

To · OPUS

Opus Audio Codec

A modern low-latency lossy codec excellent for speech and music across all bitrates.

Typical uses
VoIP, podcasts, real-time streaming.

— FAQ

Frequently asked.

Is ALAC to OPUS conversion free?

Yes. LocalConvert is completely free, with no signup and no per-file or per-day limits.

Do my files get uploaded anywhere?

No. ALAC to OPUS conversion happens entirely inside your browser using WebAssembly — your file never leaves your device.

What's the maximum file size?

There's no fixed cap — the practical limit is your device's available memory. Very large files may take longer or fail on low-RAM devices.

Does it work offline?

Yes — once the page has loaded, ALAC to OPUS conversion works without an internet connection. Re-open the page once to cache it.

Will conversion preserve quality?

LocalConvert uses the industry-standard tools (FFmpeg, ImageMagick, Pandoc) — quality matches what professionals use on the command line. Lossy formats will still lose some quality on each re-encode.

— Related

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REFERENCES

Format references

Last verified:

100% local conversion.

ALAC to OPUS is processed in your browser with WebAssembly. No upload, no tracking, no limits. Your file never leaves your device.