Are my images uploaded to a server?

No. PicSqueeze runs entirely in your browser using WebAssembly. Your images never leave your device — you can even disconnect from the internet after loading the page.

How many images can I compress at once?

Up to 20 images per batch. You can compress as many batches as you like.

What compression engines does PicSqueeze use?

Open-source engines compiled to WebAssembly: MozJPEG for JPEG, OxiPNG for PNG, and libwebp for WebP — the same engines behind Google's Squoosh, with additional tuning such as skip-if-larger protection and dimension-aware quality.

Does compression remove EXIF and GPS metadata?

Yes. Re-encoding strips EXIF, GPS location and other metadata from your images, which is a privacy win when sharing photos.

How does Target Size mode work?

Enter a size in KB and PicSqueeze binary-searches the best quality that fits under your target. If quality reduction alone isn't enough, it gradually downscales the image until it fits.

Compress images right in your browser

Batch up to 20 JPEG, PNG or WebP images. Hit an exact KB target, convert formats, compare quality — your files never leave your device.

No uploads · works offline MozJPEG OxiPNG libwebp Open-source WASM engines

🖼️

Drop up to 20 images here — or click to browse

JPEG · PNG · WebP · GIF · AVIF · BMP · you can also paste with Ctrl/⌘+V

0/20 0 B

⚙️ Mode

Finds the sweet spot automatically. Files that wouldn't get smaller are left untouched.

🔁 Output format

Auto keeps each image's format. WebP usually compresses 25–35% smaller than JPEG at the same visual quality.

📐 Max dimension

Large photos for the web rarely need more than 1920px. Resizing uses progressive half-stepping to keep details crisp.

Advanced engine tuning

Skip-if-larger guard (recommended) JPEG progressive + optimized Huffman WebP sharp YUV (crisper edges, slower)

🧊 OxiPNG effort

Nothing is uploaded — compression runs on this device via WebAssembly.

Add images to get started — everything stays on your machine.

How the compression works

PicSqueeze compiles the same open-source encoders used by Google's Squoosh to WebAssembly, then adds its own tuning layer on top. Here is exactly what happens to your files:

🧠 Smart mode

Quality is chosen by resolution: full-resolution photos get a slightly more aggressive quality than small UI assets, because size hides detail. Every result is checked against the original — if the output isn't smaller, the original file is returned untouched (skip-if-larger).

🎯 Target size

Binary search over the quality range (≤ 8 probes) finds the highest quality that stays under your KB budget. If quality alone can't get there, the image is downscaled in small steps until it fits — and the result is labeled so you know.

🔬 Quality score

Each result gets an SSIM quality score computed against the original — a perceptual metric (0–100%) that approximates what your eyes would notice, so you can trust the savings without pixel-peeping.

Engine	Used for	Tuning applied
MozJPEG	JPEG encode	Progressive scan, optimized Huffman coding, trellis quantization-table search, dimension-aware quality (76 / 72 / 80 rules)
OxiPNG	PNG (lossless)	Real lossless optimization — filter & compression-strategy search, alpha channel optimization, 3 effort presets. Pixels stay 100% identical.
libwebp	WebP encode	Method 5+ encoding, sharp YUV conversion for crisper chroma edges, auto-filter under low quality, SIMD build when available
🛡️ Guards	—	Skip-if-larger · EXIF/GPS metadata always stripped · 36 MP memory guard · progressive half-step resizing

FAQ

Short answers to the questions people actually ask.