Quick answers to the most common questions about how Filesmith works.
Yes — completely free, no strings attached. No subscription, no premium tier, no watermarks, no file limits. You don't even need an account.
The site is supported by ads, which is how the lights stay on. That's the only catch, and it costs you nothing.
Your files never leave your device. All converting, compressing, and editing runs directly in your browser using WebAssembly and the Canvas API — the same technology your browser uses to render games and video.
There is no server receiving your files. We couldn't see them even if we wanted to. The moment you close the tab, they're gone.
Audio and video conversion is powered by FFmpeg — a professional-grade open source media engine. Because FFmpeg is a large file (~30 MB), it loads from a CDN the first time you use it rather than being bundled into the page.
After that first load, your browser caches it, so repeat visits work much faster. Importantly, your actual media files still never leave your device — only the FFmpeg engine is downloaded, not your files.
Image conversion works fully offline since it uses your browser's built-in Canvas API with no external dependencies.
There's no hard limit imposed by Filesmith — we don't set a cap. The real limit is your device's available memory, since everything is processed locally in your browser.
In practice, images of any typical size work without issue. For video, very large files (several GB) may be slow or run into browser memory limits depending on your device. If a file fails to process, try closing other tabs to free up memory and try again.
Filesmith works on any modern browser that supports WebAssembly — which is essentially all of them. Chrome, Firefox, Safari, and Edge are all fully supported on desktop and mobile.
For the best experience, we recommend using an up-to-date version of Chrome or Firefox. Very old browser versions (pre-2018) may not support all features.
Yes — for images. You can drop an entire folder or select multiple files at once, then convert and download them individually or hit Convert All to process the whole batch in one go.
Audio and video files are handled one at a time since each conversion is CPU-intensive. You can still queue them up in the sidebar and work through them without re-uploading.
This can happen when converting between formats with different compression characteristics. For example, converting a highly compressed JPG to PNG will almost always produce a larger file — PNG is lossless and doesn't compress photos as aggressively.
For the smallest file sizes, WEBP and AVIF are the best choices for images — they offer significantly better compression than JPG at the same visual quality. For audio, MP3 or AAC at a lower bitrate will reduce file size. You can also try lowering the quality slider before converting.