TinyPNG alternative

If you are hitting TinyPNG's free limits — 20 images at a time, 5 MB each — or you would rather not upload work files to somebody else's server, this compressor does the same job in your browser and takes files ten times larger. It also reads three formats they do not: HEIC straight off an iPhone, TIFF out of a scanner, and BMP. The one place to stay with TinyPNG is a photograph you need to remain a PNG: they reduce its palette and this does not, so their file will be smaller.

TinyPNG's reputation rests on lossy PNG quantisation — cutting a PNG's palette down so cleverly that the loss is invisible — and it is genuinely excellent at it. This tool compresses PNGs losslessly instead: real compression, often most of the file, but every pixel unchanged. On a photograph saved as a PNG, quantising beats that, so TinyPNG will hand you the smaller file.

Almost nobody runs out of TinyPNG's twenty images. They run out of megabytes. A photo straight off a modern phone is routinely 8 to 15 MB, and a camera raw export or a screenshot of a 4K display clears 5 MB without trying — so the files most worth compressing are exactly the ones the free tier turns away. This tool takes 50 MB per image, because the work happens on your own machine and there is no upload to pay for. That is also why the limits are shaped differently: a server has to charge for bytes it receives, and a browser does not.

Your browser already contains a complete image pipeline — it decodes and re-encodes pictures every time you open a web page. This tool uses that pipeline directly, so the image is read, re-encoded and handed back without a single byte going to a server. You can watch it in your browser's network tab, and you can pull out the network cable after the page loads and it will still work. It matters for the boring cases more than the dramatic ones: a client's unreleased product shot, a scan of something with an address on it, anything covered by a contract that says where files may be sent.

The reason a browser tool could not previously compete on PNG is not the one people assume. It was not that PNG is hard — it is that browsers save PNGs at a fast, low compression setting, and every tool built on a canvas simply handed that file back. Running a real optimiser over it changes the picture entirely: an 833 KB canvas PNG measured at 127 KB here, with every pixel identical.

What TinyPNG still does that this does not is reduce the palette — throwing away colours the eye will not miss, which is lossy and which wins on photographs. So the honest split is by what the image is. A logo, a screenshot, a diagram, anything with flat colour: the lossless route here will usually be within sight of theirs, at any file size and with no daily count. A photograph that must stay a PNG: theirs will be smaller. A photograph that does not have to stay a PNG should be WebP or AVIF, and both of those are one item up the format menu.

If your goal is the smallest file rather than specifically a PNG file, converting is worth more than compressing. WebP typically produces noticeably smaller images than PNG or JPEG at matching quality, and it keeps transparency, so it replaces PNG in the one job PNG is usually kept for. This compressor converts to WebP by default for that reason, and every browser released in the last several years reads it.

AVIF is smaller still — usually another twenty to thirty per cent below WebP — and it is in the format list here too. The catch is time rather than support: no browser can write AVIF, so the encoder is a megabyte of WebAssembly that arrives on first use and then takes seconds per photo rather than milliseconds. Worth it for images going on a page that people will load repeatedly; not worth it for a one-off email attachment.