Any file up to 500 MB. Drop several files and they come back as one ZIP. Many image, audio and video conversions run in your browser; anything else is uploaded and removed within the hour.
Convert your OPUS audio files to M4A format quickly and easily. This tool is perfect for users who need to make their audio files compatible with Apple devices and legacy media players.
OPUS is a highly efficient, open-source audio codec often used for streaming and VoIP, whereas M4A is a container format based on the MPEG-4 standard, widely supported by Apple’s ecosystem. Converting OPUS to M4A involves wrapping the audio stream in an MP4-based container structure. While both formats are lossy, this process transitions your file from the Ogg-based architecture to the more ubiquitous AAC-compatible structure preferred by iTunes and QuickTime.
Since both formats use efficient compression algorithms, the conversion maintains high fidelity, and the resulting file size changes only insignificantly.
We built this project so anyone can convert files without paywalls, accounts, or hidden limits. Here is what that promise means in practice.
Every converter on ConvertX is free to use: no trials, no premium tiers, and no credit packs. We will never put core conversion features behind a subscription. Whether you convert one photo or a hundred files a week, the price stays zero.
Many image, audio, and video conversions run entirely in your browser. Your files never leave your device for those jobs. When server processing is required for documents or specialized formats, uploads are handled securely and removed automatically — typically within one hour.
A quick guide to strengths and trade-offs of popular formats — so you pick the right one before converting.
Music, podcasts, voice recordings, and sound effects.
Common extensions: MP3, WAV, FLAC, OGG, AAC, M4A, OPUS
Raster and vector graphics for web, print, and photography.
Common extensions: PNG, JPG, WebP, AVIF, GIF, SVG, HEIC, TIFF
Office files, PDFs, ebooks, and plain text.
Common extensions: PDF, DOCX, XLSX, PPTX, ODT, EPUB, TXT
Clips, streams, screen recordings, and movies.
Common extensions: MP4, WebM, MOV, MKV, AVI, MPEG
