A free TinyPNG alternative

The two limits people run into

TinyPNG’s free tier is 20 images at a time, 5 MB each. The count is rarely the problem; the 5 MB ceiling is. A photo straight off a modern phone or camera regularly exceeds it, which means the images most in need of compressing are exactly the ones it turns away.

Their format conversion is separately capped at three images for free users.

The different approach

TinyPNG uploads your image, compresses it on their servers with a genuinely clever quantisation algorithm, and sends it back. That is why there is a size cap — bandwidth and CPU cost them money per image.

Toolerax’s compressor runs in your browser instead, using the canvas encoder your browser already ships. Nothing is uploaded, nothing is metered, and the only ceiling is what your own machine can hold in memory — a 40 MB camera RAW export is not a problem.

There is a real trade-off here and it is worth stating plainly: for PNG images with few colours, TinyPNG’s output is usually smaller than ours. Their palette quantisation is better than what a browser canvas can do. For JPEG and WebP photographs — the bulk of what goes on a web page — the difference is negligible, and you get a quality slider instead of a black box.

The setting that beats both

Compression is the second-biggest lever on image weight. The biggest is dimensions. A phone photo is around 4000 pixels wide; the article it illustrates displays it at 800. Compressing the 4000px version is optimising the wrong thing — you are still shipping twenty-five times more pixels than the screen uses.

Resize first with Image Resizer, then compress. That order routinely turns a 6 MB photo into something under 100 KB with no visible difference on the page. How to compress images for the web walks through it properly.

Where TinyPNG is the better choice

• Flat-colour PNGs — logos, icons, screenshots with few colours. Their quantiser is the best free one available and we do not match it.
• Batch work. Twenty images dropped in at once, compressed, downloaded as a zip. We handle one image at a time.
• Automation. Their API, WordPress plugin and Photoshop plugin have no equivalent here.

Where Toolerax is the better choice

• Files over 5 MB — no ceiling, because there is no upload.
• Images you should not upload — client photos, product shots under embargo, anything containing personal information.
• You want to see the trade-off. The quality slider updates the preview and the resulting file size live, so you choose the point where it still looks right.
• Anything beyond compressing. Resize, crop, convert, make AVIF, rotate, remove the background — all in the browser, all free.

Common questions

Will my images be as small as TinyPNG’s? For JPEG and WebP photographs, yes, near enough. For flat-colour PNGs, often not — that is their speciality. Try both if a particular PNG matters.

Is there a file size limit?Not one we impose. Very large files are limited by your browser’s memory, not by a plan.

Do you keep the images? We never receive them. The compressor runs in your browser — check the Network tab if you want to confirm it.

Should I use WebP or AVIF instead? Often, yes — both compress better than JPEG. Image Converter handles WebP and Image to AVIF the newer format; PNG vs JPG vs WebP covers when each one wins.