Why this exists

The problem with uploading

Converting a photo, trimming a clip or pulling the audio out of a video are small jobs. Your phone does harder work than that every time it plays a video. Yet the normal way to do any of them online is to send the file to a stranger’s server, wait, and download it back.

That trade made sense in 2008, when browsers could not do the work. It does not now. What it leaves behind is a copy of your file on someone else’s machine, a privacy policy you did not read, and a queue you wait in — for a job that takes two seconds locally.

The files people convert are not trivial either. Passport photos for a visa application. A recording of a meeting. Photos of their children. Unreleased work. The habit of uploading them to whichever site ranks first is worth breaking.

That is not a knock on the big converters — they convert documents, ebooks and CAD that no browser can open, and each comparison says plainly where they are the better choice. The difference for images, video and audio is only where the file goes.

How this works instead

Every tool here runs inside your browser tab. Images go through the same codecs your browser already uses to display them. Video and audio use WebCodecs, which is the hardware encoder in your device — the one video calls use. For formats browsers cannot handle natively, the page loads FFmpeg compiled to WebAssembly and runs it locally.

There is no upload endpoint. Not a disabled one, not one behind a flag: the site is static files, and none of them accept a file. That is why the claim can be made without asking you to trust anyone — you can watch the network panel stay empty while a file converts.

The side effects are nice. It works with no internet once a page has loaded, there is no size limit beyond your device’s memory, nothing is queued behind other people’s files, and there is nothing to delete afterwards.

What it will not do

• Upload your files. Anywhere, for any reason, including analytics.
• Watermark results. There is no premium tier to push you towards.
• Ask for an account. There is nothing to store, so there is nothing to sign in to.
• Load third-party scripts. No trackers, no tag managers, no fonts from a CDN.
• Publish a tool that does not work. Tools still being built are listed without a link rather than given a page that wastes your time.

How these pages are written

Every tool and conversion page is built around a converter that runs on the page itself. The writing is there to help you decide whether to convert, which settings matter and what you will get back, and a tool gets a page only once it works. The guides answer the questions that come before and after a conversion.

The 419 conversion pages are put together from one set of notes about each format: how it compresses, what it keeps, where it opens and how big it gets. The paragraphs on a page are chosen by what is true of that particular pair, which is why PNG to JPG warns you about transparency and WAV to MP3 does not. The pairings people use most also have a note written for them specifically. Pairings almost nobody needs, such as between two formats that have both faded, do not get a page, although the converters still handle them.

Anything presented as a test result comes from running files through these tools, and when you convert an image, the before-and-after quality score is measured on your own file.

If something here is wrong, please email [email protected]. Corrections are made in the notes, so they reach every page that uses them, and a page’s “updated” date changes only when its content does.

Where it is up to

25 of 66 planned tools work today, across 420 conversion pairings. The rest are listed on the tools page marked as unfinished, and they get linked the day they work.

The upload limits page is kept as a public reference with the date each rule was last checked, because most pages quoting those numbers are years out of date. If you find one we have got wrong, please tell us.