1 MB is the common email attachment and chat upload limit. At this size the quality loss is usually invisible.
Nothing is uploaded. There is no server side to upload to.
Most compressors make you guess: move a slider, check the file size, move it again. That works when you just want "smaller". It fails when the rule is a hard number — a 100 KB cap on a job application form, a 2 MB limit on a portal upload, a 5 MB ceiling for an email attachment. This tool works backwards from the limit: it searches for the highest quality that still lands under your number, and only shrinks the pixel dimensions if quality alone cannot get there.
JPG is the safe default: photographs and screenshots, works everywhere, accepts every job portal and form. WebP gets the same picture noticeably smaller at the same visual quality, and every current browser supports it — use it when the upload target is a website or an app, not an old form. PNG is lossless, so there is no quality setting to trade away: to reach a target size the tool has to reduce pixel dimensions, which is why a PNG at 50 KB looks softer than a JPG at 50 KB.
Is my image uploaded anywhere? No. The compression runs in your browser using the Canvas API. You can disconnect from the network after the page loads and it still works.
What if my file cannot reach the target? The tool says so and hands you the smallest result it could produce, rather than silently missing. Very small targets usually require reducing dimensions, which it does automatically.
Does it keep EXIF or metadata? No — re-encoding through Canvas drops metadata such as GPS location. That is usually what you want before posting a photo publicly.