Are my audio files uploaded to any servers?

No. Ucha operates 100% serverless and client-side. All decoding and encoding processes happen locally inside your browser's memory sandbox. Your data never leaves your computer.

Can I convert multiple audio files at once?

Yes! You can load dozens of audio files. The converter queues and processes them locally, allowing you to download them individually or package them as a single ZIP archive.

What formats does the Audio Converter support?

The converter can read/decode any audio format natively supported by your browser (including MP3, WAV, AAC, M4A, OGG, WebM, and FLAC). It supports encoding and saving files in 21 formats locally.

Is there a file size limit?

No. Since conversion occurs locally in your browser's sandboxed RAM, the only limit is your machine's physical hardware capacity.

Free Online Audio Converter

Convert and compress audio files locally. 100% secure, browser-based batch processing with no server uploads.

audiotrack

Drag & drop files here, or click to browse

Supports MP3, WAV, AAC, M4A, OGG, WebM, and FLAC

Available Converters

Audio Converters

Browse every audio format we support — each opens a dedicated converter interface locally.

How to Batch Convert Audio Files Online Locally

Ucha provides a highly secure utility to manage your sound formats. Our converter encodes your media streams locally using HTML5 Web Audio and lightweight compiled encoder frameworks, preventing credentials leaks, hacks, or privacy leaks. Follow these simple steps:

Drag & Drop Media: Drag multiple files (MP3, WAV, AAC, M4A, OGG, FLAC) into the drag-drop dotted container above, or browse directly from your phone or desktop.
Configure Formats: Select your targeted output format (MP3, WAV, FLAC, AAC, M4A, OPUS, OGG, etc.). For compressed target formats, select your preferred bitrate (up to extreme 320 kbps quality).
Sample Rate Adjustments: Keep sample rates and channels matching your source tracks, or convert to custom samples (44.1kHz standard, 48kHz for high-fidelity audio).
Execute locally: Click "Convert All Tracks". Our background Web Workers will process them concurrently without blocking browser operations.
Download Outputs: Download files individually once they reach 100% conversion, or click "Download All ZIP" to save all outputs into a single packaged ZIP archive instantly.

Frequently Asked Questions

How does in-browser audio conversion work?

When you load a file, your browser uses native Web Audio decoders to decode the audio stream into raw PCM buffers. We pass this data to `lamejs` running in a multi-threaded Web Worker to re-encode the audio into MP3, or write a custom header to export WAV files.

Are my audio files secure?

Absolutely. Because we do not upload files to server systems, there are no databases, server queues, or cloud systems processing your records. Once the tab is closed, the memory is deleted.

Can I convert M4A to MP3?

Yes. Almost all modern browsers support M4A/AAC decoding. The application decodes the M4A stream and encodes it directly to MP3 inside your local browser.

Can I work offline?

Yes! Once this page has loaded, you can disconnect from the internet and convert files offline since all logic runs client-side.