Image Resizer
Set exact pixels, a percentage, or a social-media preset. Choose whether to fit, crop or stretch when the shape differs — and keep your file's format.
Dimensions
What this tool does
Upload an image, choose new dimensions, download the result. The resizer uses your browser's high-quality resampling through the Canvas API, runs entirely on your device, and writes a new file in the same format you gave it — JPEG in, JPEG out — so sizes stay sensible.
Three ways to set a size
- Exact pixels — type a width or height; with the lock on, the other dimension follows the original proportions.
- Scale — 25%, 50%, 75% or 200% of the original, ratio locked.
- Presets — common web and social sizes. Choosing one unlocks the ratio and shows the fit options below.
Fit, Crop or Stretch
When the target shape differs from your image you have to decide what gives. Fit keeps proportions and shrinks the image to sit inside the box, so the output may be slightly smaller than the preset in one direction. Crop produces the exact preset size by trimming equally from the longer sides — right for headers and thumbnails where the edges don't matter. Stretch forces the exact size and distorts; it's rarely what you want, but occasionally it is.
Tips
- Resize first, compress second — the compressor works better on the final pixel count.
- For retina screens, export at 2× the CSS size you'll display (a 600 px-wide image slot wants 1200 px).
- Don't upscale more than 2×; browsers can't invent detail.
- Transparent PNGs stay transparent; transparent images that arrive as JPEG are composited on white because JPEG has no alpha.
Frequently asked questions
How do I resize an image without distorting it?
Leave the aspect-ratio lock on and type either a width or a height — the other updates automatically. If you use a preset whose shape differs from your image, choose Fit (shrinks to fit inside the box, keeps proportions) or Crop (exact size, trims the excess from the centre). Stretch is there if you really do want to distort.
What social-media sizes are built in?
Instagram post 1080×1080 and story 1080×1920, X/Twitter header 1500×500, Facebook cover 820×312, LinkedIn banner 1584×396, YouTube thumbnail 1280×720, plus 1080p, 720p and the 1200×630 Open Graph size. You can type any other dimensions directly.
Will resizing lose quality?
Scaling down with the browser's high-quality resampler is essentially lossless to the eye. Scaling up cannot invent detail: 2× is usually acceptable, beyond that you will see softness. The output keeps your input format — JPEG stays JPEG at quality 92, WebP stays WebP, everything else becomes PNG — so you don't get a surprise 8 MB PNG from a 2 MB photo.
Can I resize by percentage?
Yes — the Scale buttons apply 25%, 50%, 75% or 200% to the original dimensions with the ratio locked. Type your own numbers for anything else.
Is there a maximum size?
Output is capped at 8192 pixels on either side, which is larger than any screen and keeps memory use reasonable on phones. Inputs bigger than that are fine; they just can't be resized larger than the cap.
Does this upload my photo?
No. The page is static and has no upload endpoint. Your browser reads the file, the Canvas API resamples it on your device, and the result downloads straight to your disk. It works offline.