About oCompress

An independent site since 2021

oCompress is a small, independent website. It started in 2021 as a collection of pages that pointed visitors to compression tools for each file type, and its pages are published in English and 22 other languages. It is not part of a software company, does not sell an app or a subscription, and has no connection to the makers of the formats and programs mentioned on its pages.

Rebuilt in 2026 with our own compressors

The early version relied on other websites to do the actual compression. That meant your files were uploaded to servers we did not control, and the results depended on services we could not improve. In 2026 we rebuilt the site from scratch around a different idea: the compression should happen on your own device.

Today every tool on oCompress is our own code running in your browser. It builds on well-tested open-source codecs, such as MozJPEG, OxiPNG, libwebp and SVGO for images, the Mediabunny library with the browser's built-in video and audio encoders plus LAME and libFLAC for MP3 and FLAC, and open-source PDF and ZIP libraries for documents. We wrote the parts that connect them: the interface, the presets, the handling of Office files and PDFs, and the checks that make sure you never receive a file larger than the one you started with.

What we care about

• Your files stay with you. Nothing you compress is uploaded, stored or seen by us.
• Honest results. We show the real size before and after, explain what was changed, and do not promise percentages that depend on your file.
• Practical guidance. Each format page explains the format itself and which settings suit email, the web or an archive, so you can decide with confidence.
• Clear limits. Where a browser cannot do the job, such as with WMA audio or old binary Office files, we say so and point to alternatives.

How the site is funded

oCompress is free to use, without an account, a watermark or a limit on the number of files. The costs of the domain, the server that delivers the pages and the development are paid by advertising. Ads are served by Ezoic and Google AdSense and appear around the content of the pages; they are never placed inside the tool area or next to download buttons. How advertising and analytics use cookies is explained in the privacy policy.

Get in touch

We read every message. If a file does not compress as you expected, a format you need is missing, a translation sounds wrong or you found a mistake in our explanations, write to us through the contact form. Screenshots help a lot; please do not send the file itself unless we ask, and never send anything confidential.

To learn more about the technology, read how it works or browse the FAQ.