Re-compress PNG with OxiPNG and JPG with MozJPEG to cut file size — all processing happens locally, nothing is ever uploaded.
Add one or many — PNG, JPG & WebP. Or paste with ⌘/Ctrl + V
PixKit runs the Squoosh codecs — OxiPNG for lossless PNG and MozJPEG for quality-controlled JPG — as WebAssembly inside your browser tab. Click Optimize PNG for a pixel-identical smaller file, or set the JPG quality slider (50–95) and optimize; the exact before/after size is reported and nothing is uploaded.
Clean the Gemini sparkle, then finish the job — crop, resize, convert and adjust without uploading a single pixel.
Reverse-alpha math restores the true pixels under the Gemini logo — no blur, no AI guesswork.
Crop to any aspect ratio with draggable handles, then resize to exact pixels or quick scales.
Export to PNG, JPG or WebP with a quality slider and a live file-size estimate.
Every tool runs locally with undo/redo. Nothing is uploaded — it even works offline.
Best-in-class codecs, running in your tab — with the savings printed after every run.
Drag in, paste, or pick a file — the panel shows its current pixel dimensions. Any format PixKit can open can be optimized.
Click "Optimize PNG (OxiPNG)" for a lossless, pixel-identical PNG, or set the JPG quality slider (50–95) and click "Optimize JPG (MozJPEG)" for photos.
The optimized file downloads as yourimage-optimized.png or .jpg, and the status reports the exact before → after sizes and percentage saved.
Smaller hero images and thumbnails mean faster loads and better Core Web Vitals — MozJPEG at quality 75–85 is a proven sweet spot for the web.
OxiPNG losslessly shaves UI screenshots so wikis, bug reports and READMEs stay fast without a single pixel changing.
Squeeze photos under a mail server's size cap without the visible mush that aggressive generic compressors leave behind.
The lossless PNG path keeps the alpha channel exactly intact — safe for assets where recompression artifacts are unacceptable.
Optimizing images before committing keeps clones fast, and lossless PNG passes mean no reviewer will ever spot a difference.
Everything you need to know about optimizing images locally.
PixKit Optimize shrinks your images using the exact Squoosh codecs — OxiPNG for lossless PNG and MozJPEG for high-efficiency JPG — running entirely as WebAssembly inside your browser tab. Pick PNG or JPG, tune the JPG quality, and download a leaner file in seconds.
OxiPNG re-encodes PNG data without touching a single pixel, finding the smallest possible representation. It is perfect for screenshots, logos, icons and any graphic with sharp edges or transparency that must stay crisp — the alpha channel survives exactly as it was.
MozJPEG produces visibly cleaner JPGs at smaller sizes than standard encoders. Use the quality slider (50–95) to balance file size against fidelity — around 80 is an excellent default for photos and complex images. After every run the status line prints the before and after sizes with the percentage saved, so you can re-run at a different quality until it's right.
Use PixKit's Compress tool when you must hit a specific file size, like a 500 KB upload limit. Use Optimize when you want the best possible encoding of the image as-is: lossless PNG for graphics, or MozJPEG at a quality you choose for photos. Both run locally; this one gives you codec-level control.
| PixKit | Typical online tools | |
|---|---|---|
| Where your image is processed | On your device — nothing is uploaded | Uploaded to the tool's servers |
| Price, accounts & limits | No sign-up or usage credits; browser safety limits apply | Free-tier caps, accounts, paywalls |
| Speed on large files | No upload or queue; speed depends on the device | Upload, wait in queue, download |
| Works offline | Yes — installs as a PWA | No connection, no tool |
| Codecs | Real Squoosh WASM builds of OxiPNG & MozJPEG, running in your tab | Opaque server-side encoders with unknown settings |
| Transparency | Lossless PNG pass keeps every pixel and the full alpha channel | "Smart" PNG modes are often lossy quantization by default |
| Feedback | Exact before → after bytes and % saved after every run | A download button and a vague "optimized!" claim |
One private editor, a tool for every job — all 100% local, no upload.