Everything that comes up often.
Clear, no-nonsense answers about how the converter works, the privacy of your files, and our business model. Don't see your question? Email us.
Frequently asked questions.
Click a question to expand the answer. Questions are ordered by how often they come up.
How does offline mode work?
From your very first visit, MediaBay's Service Worker caches the entire application: the HTML, the CSS, the JavaScript, and also the WebAssembly decoders (libheif, libavif) and the ZIP compression engine. In other words, from that point on the app becomes 100 % network-independent — you can cut your internet connection and conversion and archive generation keep working normally. For a complete offline experience, install MediaBay as an app (PWA) from your browser menu: Chrome, Edge and Safari support one-click installation.
Which formats are supported?
MediaBay accepts JPG/JPEG, PNG, WEBP, GIF, BMP, HEIC/HEIF (the iPhone photo format) and AVIF as input. As output, you can convert to JPG, PNG, WEBP or AVIF. The newer formats (HEIC, AVIF) are decoded by C libraries compiled to WebAssembly (libheif, libavif), running directly in your browser.
Why is it free?
The service is funded by ads displayed on the page. Your images, however, are never accessible server-side — they stay in your browser's memory from start to finish. So we don't resell any file content: it's technically impossible, since we never have access to it.
Is there a file size limit?
Yes: an application safeguard blocks any file larger than 100 MB. Since all processing happens in your device's RAM, an oversized file could exhaust that memory and crash the tab. This safeguard protects your hardware and ensures a smooth experience. In practice it's more than enough: a recent phone easily handles 20–30 MB photos, and a desktop comfortably takes 80 MB. If you still get a memory error, close your other tabs and try again.
Are my images really private?
Yes, and you can check it yourself. Open your browser's developer tools (the F12 key), go to the “Network” tab, then run a conversion. You won't see a single outbound request containing your file — only the initial script load and, possibly, requests related to advertising or analytics. The content of your image never leaves your device.
Why is my HEIC or AVIF conversion slower?
The HEIC and AVIF formats rely on modern video codecs (HEVC and AV1) that are extremely efficient at compression but costly to decode. MediaBay loads the matching WebAssembly libraries (libheif, libavif) on demand, only the first time you convert that type of file. These libraries are now hosted directly on our own servers and pre-cached by the PWA, so there's no download latency from an external service, even on the very first use. Expect a few hundred milliseconds for initialization, after which every following conversion is nearly instant.
What's the output quality?
You control the quality yourself with a slider, expressed as a percentage between 40 % and 100 %. At 90 % (the default), the visual difference from the original is imperceptible to the naked eye for the vast majority of images. For the PNG format, which is lossless, the slider has no effect.
Can I convert several images at once?
Yes, fully. MediaBay completely supports batch (bulk) processing: drop dozens of images at once, set your global options (output format, quality, dimensions), and the engine converts them all, then instantly generates a ZIP archive containing all your converted images. Just like a single conversion, nothing goes through a server — decoding, re-encoding and ZIP compression all run entirely in your browser.
What data do you collect?
None about your files (technically impossible). However, like any website, we measure traffic via Google Analytics 4 (only after your consent), and our host OVH keeps technical logs (IP address, date, browser). All the details are on our “Privacy Policy” page.
Where are your servers?
MediaBay is hosted by OVH SAS, in data centers located in France and Germany. All server-side processing (which doesn't involve your images, but the site itself) stays within the European Union, under GDPR.
Ready to convert.
Not all questions are equal — often the best answer is to try it. Run a conversion, watch what goes through your browser's Network tab, and see for yourself.