Image Resizer

Resize images to exact dimensions right in your browser.

This tool runs entirely in your browser. Your data is never uploaded, never stored, and never leaves your device.

Set an image to exact pixel dimensions — 800px wide for a blog body, 1200 × 630 for a social preview card — with the aspect ratio locked so nothing stretches, then export as PNG, JPEG or WebP.

How to use it

1Drag an image onto the drop zone; the width and height boxes fill with its real pixel size.
2Type the width you want — with Lock aspect ratio ticked, the height follows on its own.
3Pick PNG, JPEG or WebP, move the quality slider if the format is lossy, then press Resize and download.

Example

Input: A 1920 × 1080 photo, width set to 1000, Lock aspect ratio ticked
Output: Height fills in as 563, and the export is 1000 × 563px

1000 × 1080 ÷ 1920 is 562.5, and pixels have to be whole numbers, so a locked ratio is accurate to within half a pixel rather than perfect. Anything over 8000px on either side is refused.

What happens to your data

Resizing happens on a canvas element inside your browser; the file is opened through a local blob URL and never uploaded, so there is no server-side copy to worry about deleting.

Last updated August 2026

Resizing a photo is asked for in two quite different ways. Sometimes you know the exact number — 1200 by 630 for a social preview, 800 wide for a blog body, a passport size a form insists on. Sometimes you just need the picture smaller than the 4000-pixel monster your phone produced.

This photo resizer does both, with the aspect ratio locked by default so nothing stretches. Change the image size in pixels, keep the proportions, and export as PNG, JPEG or WebP.

The hard part is usually deciding which number to type. A layout that shows an image 800 pixels wide will look soft on a modern phone or laptop unless the file is about twice that, because those screens pack two or three physical pixels into every one the layout counts. The rule that follows is simple: export at roughly twice the size the image will be displayed at, and no more. Beyond that you are sending data the browser will only throw away.\n\nResize photo, change image size, resize image online \u2014 one job under three names, and the only question that matters is whether you know the number you need. If a form demands 800 by 600, type it. If you only need it smaller, halve the width and look at the result.

How it works

Toolvore draws your picture into a canvas at the size you asked for and re-encodes it there, in the page. Because pixels have to be whole numbers, a locked aspect ratio is accurate to within half a pixel rather than exactly — 1000 × 1080 ÷ 1920 is 562.5, and the export becomes 563. Nothing is uploaded; the scaling is done by the same graphics stack your browser uses to draw everything else. One thing worth knowing about scaling down: browsers do it in a single step, which is fast and slightly soft on large reductions. Going from 4,000 pixels to 400 in one jump discards nine tenths of the detail at once; stepping down in halves preserves more of the fine structure. If a large reduction comes back softer than you expected, resizing in two passes usually looks better than one. Re-encoding also costs a generation of quality each time, so it is worth doing the resize once from the original rather than repeatedly from your own output.

Common use cases

Scaling an image to exact pixel dimensions a site or form requires
Making a 1200 × 630 preview card so a link shows the right crop when shared
Reducing photo size before uploading so the page loads faster
Changing image size to fit a template without distorting it
Converting format and resizing in one step — a large PNG down to a small WebP

Frequently asked questions

How do I resize a photo without stretching it?＋

Leave 'Lock aspect ratio' ticked and type only the width. The height follows on its own, keeping the original proportions, so nothing is squashed.

Can I set exact image dimensions?＋

Yes. Untick the ratio lock and type both width and height. The picture will be distorted if the numbers do not match its proportions — which is sometimes exactly what a template requires.

Does resizing reduce the file size?＋

Usually a great deal, because there are fewer pixels to store. If you need a specific file size rather than specific dimensions, the image compressor targets a byte count directly.

Will enlarging an image make it sharper?＋

No. Scaling up invents pixels by interpolating between the ones you have; it cannot recover detail the photo never captured. Scale an image down and it stays sharp; scale it up and it looks soft beyond small increases.

Is my picture uploaded?＋

No. The resize happens on a canvas in your browser and the file never leaves your device.

What size should a social preview image be?＋

1200 by 630 pixels is the size that works nearly everywhere — it is what link previews on most platforms crop toward, and it is close enough to 1.91:1 that nothing important gets cut. Square posts want 1080 by 1080, vertical stories and reels 1080 by 1920. Where a platform gives its own number, use theirs; where it does not, 1200 by 630 is the safe default.

What does DPI have to do with pixel size?＋

For anything on a screen, nothing at all. DPI is a note attached to the file saying how large to print it, and it changes no pixels: a 1000-pixel image is 1000 pixels whether it is tagged 72 or 300 DPI. It only becomes real at print time, where 300 DPI means 300 pixels per printed inch — so a 2-inch-wide print needs 600 pixels. If a form asks for 300 DPI, what it actually needs is enough pixels for the physical size.

Why does my resized image look soft?＋

Usually because it was reduced a long way in one step, or because it was enlarged. Reduction throws detail away and the remaining pixels are averages of what was there; enlargement invents pixels that were never captured, so the result can be bigger but never sharper. If a smaller version looks soft, try the reduction in two passes. If a larger one does, the detail is simply not in the file.

Should I crop first or resize first?＋

Crop first, almost always. Cropping decides what is in the picture and resizing decides how many pixels describe it, so doing it the other way round means resizing pixels you are about to discard — and it costs you resolution, because you end up cutting a region out of an already-reduced image rather than out of the original.

Is there a limit to how large an image I can work with?＋

There is, and it comes from the browser rather than from us. Every browser caps how large a canvas it will allocate — commonly around 16,000 pixels on a side, with a further limit on total area, and lower on phones where memory is tighter. Ordinary camera and phone photographs are nowhere near it. Panoramas, stitched scans and very large screenshots occasionally are, and when a browser hits the ceiling it usually fails quietly rather than warning you, so check the result.