Image resizer
Your images never leave this device
Resizing redraws an image at a new pixel size, and the dimensions are what actually shrink the file: a photo 1200 pixels wide holds roughly a sixth of the data of the same photo at 3000. Set a width freehand, or take a preset — 1080×1350 for an Instagram post, 1280×720 for a YouTube thumbnail, 800×800 for a profile picture.
How to resize images
Fit inside never crops and never enlarges beyond the box you set, which is what you want for a gallery. Fill crops to cover the box exactly, which is what you want for a square avatar. Stretch ignores the proportions entirely and is almost never what you want, but it is there because occasionally it is.
Cropping before the platform does it for you
Every social platform enforces its own frame, and if your image does not match it, it gets centre-cropped or letterboxed without asking. Resizing to the target dimensions first is how you decide what survives rather than finding out afterwards. The presets carry the sizes the platforms document: 1080×1350 for the 4:5 Instagram post that takes the most vertical space in the feed, 1080×1920 for a story or a Reel, 1200×630 for Facebook, 1600×900 for X, 1200×627 for LinkedIn, 1280×720 for a YouTube thumbnail and 1000×1500 for a Pinterest pin. These do move; if something crops oddly, check the platform’s current help page rather than assuming the arithmetic is wrong.
A story or a Reel is 1080×1920, but not all of that frame is yours. Instagram lays the account row over the top and the caption over the bottom, which on a story puts roughly the top 14% and the bottom 20% under interface, and on a Reel about the top 12%, the bottom 26% and the right 20%, where the caption and the action buttons sit. Those pixels are not cropped away, they are covered, so resize to the full 1080×1920 and treat the band in the middle as the part anyone will actually read.
For a profile picture, one 800×800 file covers every common platform, because they all downscale it themselves — Instagram and Facebook to 320, X and LinkedIn to 400, Discord to 512, WhatsApp to 640. Nearly all of them then mask it to a circle, which loses about 21% of the square, so keep anything that matters well inside the middle. GitHub is the exception and uses a rounded square, so a little more of the corners survives there.
A word on upscaling: the tool will enlarge an image if you ask it to, and the result will be soft, because there is no detail to recover. Start from the largest original you have. Downscaling from 3000 pixels to 1080 costs nothing visible; going the other way always shows.
Reading an image before you change it
Press Keep the original size, or clear the width field, and nothing is resized: each file comes back listing its real pixel dimensions and its weight, which is often the whole question. That also settles the print one, because print size is arithmetic on the pixels. Divide each side by 300 for inches at 300 dpi, which makes 2480 × 3508 an A4 page and 3508 × 4961 an A3. The dpi figure stored inside a file changes none of that. It is a note to the printer about how large to lay the pixels down, and editing it neither adds pixels nor removes any.
What people use it for
- Cropping one photo to every Instagram placement
- One profile picture at the size every platform wants
- A square crop for a product listing or album artwork
- Post images at each platform’s documented size
- Reading an image’s real dimensions and weight without uploading it
- Working out whether a photo has the pixels to print at A4
- Checking what a batch weighs before and after a resize
Questions
No. The browser decodes and redraws them locally. You can disconnect from the network and the tool still works.
800 × 800 covers every common platform, because each one downscales it to its own size. Anything smaller than the display size will be upscaled and look soft.
Because most platforms mask a profile picture to a circle, which loses about 21% of the square. Compose inside the circle rather than to the edges.
Fill for photographs, so the frame is covered edge to edge and the crop happens from the centre. Fit inside when nothing may be cut off, such as a diagram or a logo.
Because the platform enforces its own aspect ratio and crops to fit. Resizing to the target dimensions first is how you choose which part is kept.
Because the caption and the profile row are drawn on top of it. Reckon on the top 14% and the bottom 20% of a story being covered, and the top 12%, bottom 26% and right 20% of a Reel. Resize to 1080×1920 and keep anything that has to be read in the middle band.
4:5 portrait at 1080 × 1350. It takes the most vertical space in the feed, which is why it is the default choice for a single image.
They are the dimensions the platforms document, and they do change. If something crops oddly, check the platform’s current help page.
Take one of the square presets and set Fill. It crops from the centre, keeping as much as the square allows; if the subject sits off to one side, crop it manually first. Which square depends on where it is going: 1080 for social, 2048 for product photography, 3000 for podcast or album artwork, 512 for an icon.
JPEG for photographs, PNG when you need transparency or crisp flat colour, WebP when you want both and know your audience’s browsers support it. Watch for the trap in the other direction: PNG is lossless, so saving a photograph as one routinely comes out larger than the JPEG you started with.
Around 80 is the usual sweet spot for photographs, and about 85 for anything a platform will re-compress. Below about 60 the artefacts become visible in flat areas such as sky.
Downscaling from a larger original does not, visibly. Upscaling does, because there is no detail to recover — start from the biggest file you have.
Yes, as a side effect: the image is redrawn from pixels, so camera model, timestamps and GPS coordinates are not carried over.
Press Keep the original size, or clear the width field, and drop the file in. Nothing is resized and the list reports its real pixel dimensions and its weight. Everything stays on your machine, which is the reason to do it here rather than upload it somewhere.
Divide each side by 300 for the size in inches at 300 dpi. 2480 × 3508 is an A4 page and 3508 × 4961 is A3. The dpi number stored in the file makes no difference to that; it tells a printer how large to lay the pixels down and does not create any.
Dimensions are pixels; file size is bytes on disk. A large image can still be a small file if it compresses well. The list shows the size each file was written at along with its bytes before and after, so you can see what the resize cost and what it saved.
Yes. There is no upload and no queue, so the only limit is memory. More than one file comes back as a single ZIP.