What this resizer does
Drop a PNG, JPEG or WebP, say how big you want it, and download the result. Your browser decodes the file and redraws it, so nothing travels to a server. The control above measures the real pixel size of what you dropped and prints the answer before you commit to it: 1920 × 1080 → 800 × 450.
Three ways to state a size
Exact size suits an upload form that demands numbers. Both fields open on the size of your first file, so you edit one number instead of guessing two. While proportions are locked, the other field follows: type 800 into the width of a 1920 × 1080 photo and the height becomes 450. Unlock them when the target is a fixed rectangle and you accept the stretch.
Percent takes a fraction of what you started with, in three steps: three-quarters, half, a quarter. Reach for it when the exact number matters less than "smaller than this".
Longest side caps the longer edge and lets the shorter one follow. Forums and mail systems phrase their limits this way ("nothing wider than 1600 px"), and one number then covers portrait and landscape files in the same batch.
Nothing gets enlarged
Ask for 3000 px from a 1200 px image and you get 1200 px back. Enlarging cannot recover detail the file never recorded; it spreads the pixels you have over a wider grid, and the edges go mushy. A file that hits that ceiling is marked "already smaller" in the preview, so a number that stops moving is never a mystery. When your image already sits at or below the size you asked for, the original bytes come back untouched.
Formats stay put
A PNG leaves as a PNG and a WebP as a WebP. A JPEG stays a JPEG, though the extension settles on .jpg even when it arrived as .jpeg. Filenames pick up their new dimensions, so portrait.jpg becomes portrait-800x450.jpg and a batch stays readable in your downloads folder. Reductions past 2:1 on either edge go through halving steps before the final draw, which keeps fine lines from breaking up.
The encoder rewrites JPEG and WebP at high quality, since a smaller picture has to be drawn from scratch. GIF and BMP get a refusal: your browser reads both and writes neither, and a PNG wearing a .gif name would cost you more trouble later than a clear no now.
Where it stops
- Enlarging. A 400 px image cannot leave here at 4000 px.
- Cropping. The whole frame comes through. Cutting a shape out of it is a different job.
- A file-size target. Fewer pixels means fewer kilobytes most of the time, but this tool aims at dimensions rather than at 200 KB.
- Animation. An animated WebP comes out as one still frame.
Common questions
Does anything upload?
No. The page does the work and your files stay on your machine.
Can I resize a whole batch?
Drop as many files as you like, up to 50 MB each. One rule covers all of them, so Percent and Longest side handle a mixed set without any arithmetic from you.
Will the picture look soft?
Shrinking sharpens more often than it blurs, since the same detail lands in fewer pixels. Text and thin diagonal lines show a heavy reduction first, so check those at full zoom.
What happens to transparency?
PNG and WebP keep their alpha channel.