Image Tinifier

About this tool

Shrink a JPEG's file size using mozjpeg — the same encoder that powers TinyPNG-style compression — running locally in your browser via WebAssembly. It uses trellis quantization and optimized Huffman tables to squeeze out far more redundancy than a browser's built-in JPEG encoder, so you get noticeably smaller files at the same visual quality. Nothing is uploaded; the ~250KB encoder loads once on first use and everything else runs on-device.

Frequently asked questions

How is this different from the Image Compressor tool?

The Image Compressor uses the browser's built-in canvas.toBlob encoder — fast, but not very efficient, and re-encoding at high quality can even produce a larger file than the original. This tool uses mozjpeg, a purpose-built compression library, which gets much closer to TinyPNG-sized output at the same quality slider value.

Why does the first compression take a moment?

The mozjpeg encoder is a ~250KB WebAssembly module that loads on your first compression and is then cached by your browser — later compressions on the same page are much faster.

Why is JPEG the only output format?

TinyPNG's dramatic PNG shrinkage comes from lossy palette quantization (reducing to a few hundred colors), which is a different technique from JPEG compression and isn't included here. For PNGs, try the Image Format Converter to convert to WebP instead, which is usually much smaller than PNG at similar quality.

What quality level should I use?

70–80% is a good starting point — mozjpeg's smarter encoding means you can often go lower than you would with a typical JPEG encoder before artifacts become visible.

Is my image uploaded anywhere?

No. Decoding, compressing, and downloading all happen locally in your browser — the image never leaves your device.