Free · no signup · never uploaded
Image Resizer
Resize an image by pixels, percentage, or to fit a maximum — and compress it to a smaller file. Everything happens in your browser; your image is never uploaded.
Short answer
To resize an image, drop it in below, set a new size — by percentage, exact width or height (aspect locked), or a fit-within box — and download. To reduce the file size, lower the quality or export as JPEG or WebP. It all runs in your browser, so nothing is uploaded and it works offline.
Resize vs. compress
Resizing changes the image’s dimensions in pixels — useful for fitting an upload limit, a profile photo, or a print size. Compressing shrinks the file size at the same dimensions by lowering quality or switching to an efficient format. They stack: resize to the dimensions you need, then compress to hit a file-size target like 1 MB or 200 KB.
Which format should I use?
- JPEG — best for photos and the most compatible everywhere.
- WebP — usually the smallest file at the same quality; ideal for the web.
- PNG — lossless, keeps transparency and sharp edges; best for graphics, logos, and screenshots.
How we calculate this
Resizing and compression happen locally in your browser — here's exactly how:
- Decode. your file is decoded to a bitmap in the browser (via createImageBitmap) — never uploaded to any server.
- Target size. new dimensions come from your input — a percentage, an exact width or height (aspect-locked), or a fit-within box that never upscales past the original.
- Draw. the bitmap is drawn to an HTML canvas at the target size with high-quality smoothing.
- Encode. the canvas is exported with canvas.toBlob at your chosen format and quality; JPEG/WebP apply lossy compression, PNG stays lossless.
Assumptions
- Everything runs client-side; very large images are limited only by your device's memory.
- Enlarging can't recover detail that isn't there — 'fit' mode won't upscale.
- Re-encoding a lossy format (JPEG/WebP) discards some data each time; keep quality high to minimize it.
Last reviewed: July 19, 2026
Frequently asked questions
How do I resize an image?+
Drop your image in, choose a new size — by pixels (width and height), by percentage, or to fit within a maximum — and download the result. With aspect ratio locked, setting one dimension fills in the other automatically so the image isn't stretched. Everything happens in your browser; the file is never uploaded.
How do I compress an image or reduce its file size?+
Lower the quality slider and/or export as JPEG or WebP. JPEG and WebP are lossy formats that shrink photos dramatically with little visible change, while PNG stays lossless (best for graphics and screenshots). Resizing to smaller dimensions also cuts file size. The tool shows the before-and-after size so you can dial it in.
Are my images uploaded to a server?+
No. The resizer runs 100% in your browser using the HTML canvas — your image never leaves your device, which is faster and completely private. You can even use it offline once the page has loaded. Nothing is stored or sent anywhere.
What image formats are supported?+
You can open JPEG, PNG, WebP, and most common image formats, and export as JPEG, PNG, or WebP. WebP usually gives the smallest file at a given quality; JPEG is the most universally compatible for photos; PNG preserves transparency and sharp edges losslessly.
Will resizing reduce my image's quality?+
Making an image smaller keeps it sharp — you're discarding pixels you don't need. Enlarging beyond the original can't add detail, so this tool won't upscale in 'fit' mode. Re-encoding a JPEG at lower quality is lossy by design; keep the quality slider high (around 80–90%) for a good balance of size and clarity.
How do I resize an image to a specific size in KB?+
Reduce the dimensions and lower the quality, watching the live output size until it's under your target — a common need for upload limits (for example a 1 MB or 200 KB cap). WebP or JPEG at 70–85% quality is usually the quickest way to hit a small target while keeping the photo usable.
Related tools
- JPG to PDF — turn images into a PDF.
- Compress PDF — shrink a PDF the same private, in-browser way.
Images are processed entirely in your browser and never uploaded. Enlarging can’t add detail that isn’t in the original.