Question 1

Does uploading an image mean it goes to a server?

Accepted Answer

No. The image is read into memory with the browser File API, drawn onto a Canvas, and re-encoded there; nothing is uploaded. You can drop a confidential screenshot or a product mockup without the bytes ever leaving your machine.

Question 2

What quality should I pick?

Accepted Answer

For JPEG and lossy WebP, 75–80% is usually the sweet spot — visually indistinguishable from the original on a normal screen but 30–50% smaller. Drop to 60–65% for hero photos that need aggressive savings, and stay at 90%+ only for assets you will print or zoom.

Question 3

What's the difference between lossy and lossless WebP?

Accepted Answer

Lossy WebP (default) throws away subtle detail for much smaller files — ideal for photos. Lossless WebP compresses pixel-perfectly so the decoded image is bit-identical to the source, useful for screenshots, UI assets, or anything where you cannot tolerate any artifact. Lossless files end up bigger but still smaller than the equivalent PNG.

Question 4

Can I compress several files at once?

Accepted Answer

Yes. Drop a folder of images onto the page and the compressor processes them in one pass, showing per-file before/after sizes and the total saving at the bottom.

Image Compressor

Compression Settings

Frequently asked questions

Turning an Image into ASCII Art: How Luminance Mapping Works

Barcode Generator

Base64 Image Encoder

EXIF Viewer & Cleaner

Favicon Pack Generator

Image Format Converter

Image to ASCII Converter