About Resizo

Open a tool and the page brings the image software with it: decoders and encoders for JPEG, PNG, WebP and HEIC, compiled to run inside a browser. Your picture is read, changed and written back out by the machine you are sitting at. Nothing is uploaded, so there is no copy of your photo anywhere but on your own disk.

That also means there is nothing here to breach. No file store, no database, no account records — the deployment holds static pages and the image code, and it has no credentials for anything because there is nothing for it to reach.

There is nothing to sign up for and nothing to log in to. Every tool works the same for everyone, with the same limits and the same output, and no step ever asks who you are.

Because nothing is kept, there is no history to look back on, no dashboard, and nothing tying what you processed to a name. The absence of an account is the feature: there is no record to keep, export or delete.

A single file is capped at 20 MB and 8,000 pixels on the longest side, with an output budget of 40 megapixels. A batch takes up to 20 files totalling 80 MB. There is no quota, no queue and nothing counting how often you use it.

These are not upsell gates — there is nothing to buy. They are the size at which the job comfortably fits in the memory a browser tab is given. A photograph has to be unpacked into raw pixels to be worked on, and raw pixels are far bigger than the file: a 12-megapixel photo is about 46 MB of memory once opened, and an operation usually needs two of those at once.

So the honest limit is your own hardware, and it moves. A desktop with memory to spare will take a job an old phone will not. Every tool works the cost out before it starts and refuses a job that will not fit, with a sentence saying why and what to try instead — a smaller target, or resizing before compressing. That is deliberate: a tab that runs out of memory is closed by the operating system without warning, and on an iPhone it happens silently, so guessing and hoping would mean losing the photo you were working on.

For most of Resizo’s life the work happened elsewhere. Your file was sent to a server, a library called sharp did the resizing there, and the result came back in the reply. The argument for it was real: server hardware is predictable, one image library behaved the same for everyone, and a browser genuinely could not decode a HEIC or hit an exact kilobyte target.

That stopped being true. A browser will now run the same codecs compiled to WebAssembly, and for the common jobs it uses its own built-in image pipeline, which is quick — and none of it waits on a connection. So the argument inverted. The old design asked you to hand a personal photo to a stranger’s computer for a job your own computer could do, and no promise about deleting a file afterwards is as good as never having it.

The trade is honest and worth stating. Results now depend on the device: a big photograph is slower on an old phone than it was on a server, and a job too large for the memory the browser can spare is refused instead of being sent away to succeed elsewhere. Two formats went with the change — AVIF and GIF are no longer accepted anywhere, because there is no decoder for either one available here, and refusing them is better than pretending. What you get back is a tool that works without a connection to us doing anything but serving the page, and a privacy claim that is a fact about the software rather than a policy about our conduct.

Resizo is built and maintained by one developer. It is a free, non-commercial project: no ads, no paid tier, no accounts, no data brokered, no images retained to train anything.

• Resize Image— Change image dimensions with pixel-perfect precision.
• Compress Image— Reduce file size without visible quality loss.
• Convert Format— Convert between JPEG, PNG and WebP instantly.
• Crop Image— Remove unwanted areas with exact pixel control.
• Convert HEIC— Convert iPhone HEIC photos to universal JPEG.
• JPG to PDF— Combine photos into one PDF, in the order you choose.
• Merge PDF— Combine several PDFs into one file, in the order you choose.