Image Resizer

How this resizer works

Choose a photo using the drop area above (drag and drop, click to browse, or paste an image you copied from somewhere else). As soon as a file loads, its original width and height appear next to the input fields, and the fields fill in with that same size so you have a sensible starting point to edit from.

From there you can either type your own width and height, or pick one of the built in presets (an Instagram post, a YouTube thumbnail, a passport photo, and so on) to fill both fields at once. With Lock aspect ratio switched on, changing one dimension automatically recalculates the other so the photo never comes out stretched or squashed. Press Resize image, and a preview of the result appears next to the original so you can compare before downloading.

Why nothing gets uploaded

Every browser already contains a full 2D drawing engine, the same one that renders the photos, buttons, and text on any page you visit. This tool draws your photo onto a hidden canvas at the new size, then asks the browser to encode that canvas back into a PNG or JPG file, all using that built in engine. There is no step where the photo travels to a server somewhere to be processed and sent back: the entire operation happens on the device you're using right now, which is also why it works offline once the page has loaded and why there is no waiting for an upload before the resize even starts.

See the privacy policy for the complete, plain language explanation of what does and doesn't happen to a photo you select.

Worked example: shrinking a photo for email

Say your phone's camera produced a photo at 4032 by 3024 pixels, a common resolution for modern phone cameras, and an email attachment limit is rejecting it. Drop the photo in, then either type 1200 into the width field (with aspect ratio locked, the height field updates itself to 900) or choose a smaller preset from the list. Switch the output format to JPG and set quality to somewhere around 80, which keeps the photo looking sharp while cutting the file size dramatically compared to the original. Download the result, and it's ready to attach.

Worked example: an exact size for a passport photo

A passport or ID photo usually has to match an exact pixel size, not just look roughly right. Pick the US passport photo preset (600 by 600 pixels) from the size list, and both fields fill in automatically with the exact required dimensions. Because the preset sets both numbers directly, aspect ratio lock doesn't need to do any work here: you're choosing a fixed target size rather than scaling proportionally. See the size presets page for the full list of built in sizes and where each figure comes from.

Aspect ratio, in plain terms

A photo's aspect ratio is the relationship between its width and its height, usually written as two numbers like 4:3 or 16:9. A 4032 by 3024 photo and a 1344 by 1008 photo share the same aspect ratio (both simplify to 4:3), so shrinking one down to the other's size doesn't distort anything. Typing a new width or height with the lock switched on keeps that same ratio: the tool multiplies (or divides) both dimensions by the same factor, rather than changing one number without touching the other.

Turning the lock off is useful when you deliberately want a different ratio, for example cropping a landscape photo down into a square Instagram post, but be aware that doing so stretches or squashes the image rather than cropping it: a photo resized to a very different ratio with the lock off will look visibly distorted. For a true crop (cutting away part of the photo rather than reshaping the whole thing), a dedicated cropping tool is the better fit; this resizer scales the entire photo to the new dimensions you set.

PNG or JPG: which output format to pick

PNG keeps every pixel exactly as the resize produced it, with no additional compression loss, which makes it the safer choice for screenshots, graphics with sharp edges or text, or anything with transparency. The tradeoff is file size: a PNG of an ordinary photo is often several times larger than the same photo saved as a JPG.

JPG applies a further, adjustable compression pass on top of the resize. At quality 90 and above the difference from the original is essentially invisible to the eye while the file shrinks meaningfully; dragging quality down toward 60 to 70 shrinks it further at the cost of some visible softness in fine detail, useful when a strict file size limit (an email attachment cap, a web form upload limit) matters more than a small quality loss. There's no single correct answer here: a print destined for a photo lab benefits from PNG or a high JPG quality, while a quick chat attachment can usually take a much lower quality setting without anyone noticing.

Common target sizes at a glance

These are the most requested sizes, built into the preset picker above so you never have to look up or type the numbers yourself. The size presets page lists every built in preset with its exact dimensions and where each figure was sourced from, including print and web sizes not shown in the shortlist below.

• Instagram post: 1080 by 1080 pixels (square).
• Instagram or TikTok story: 1080 by 1920 pixels (vertical).
• Facebook shared image: 1200 by 630 pixels.
• YouTube thumbnail: 1280 by 720 pixels.
• US passport photo: 600 by 600 pixels.
• HD wallpaper: 1920 by 1080 pixels.

Resizing up versus resizing down

Shrinking a photo (making it smaller than the original) is the safe direction: the drawing engine has more source detail than it needs, so it can pick the best pixels for the smaller canvas and the result looks sharp. Enlarging a photo (making it bigger than the original) has to invent pixels that were never captured in the first place, and the result gets progressively softer and blurrier the further past the original size you push it. A modest enlargement, say 20 to 30 percent, is usually still presentable; doubling or tripling a small photo's dimensions almost always looks noticeably soft, since no ordinary resize (including this one) can recover detail that was never there to begin with. If sharp enlargement of a genuinely low resolution photo is the goal, that's a different, much heavier kind of tool (an AI upscaler, which reconstructs plausible detail rather than just stretching pixels) than a plain resizer like this one.

Picking a resolution for print, not just for screens

A screen size is measured purely in pixels, but a print size needs one more piece of information: how many of those pixels land in each inch of paper, usually written as DPI (dots per inch, though it technically means pixels per inch once you're past the printer's own internal dot pattern). A standard print quality target is 300 DPI: a photo printed at 4 by 6 inches at 300 DPI needs 1200 by 1800 pixels, and an A4 page at 300 DPI needs roughly 2480 by 3508 pixels, which is exactly the built in A4 print at 300 DPI preset in the size list above.

Printing the same file at a lower DPI (say 150 instead of 300) spreads the same pixel count across a physically larger area, which is why a photo that looks perfectly sharp on a phone screen can look soft once it's printed poster sized: the pixel count didn't change, but the DPI dropped because the same pixels now cover more paper. If a print is coming out grainy or blurry, the fix almost always involves starting from a higher resolution source rather than trying to enlarge a small photo up to the target pixel count, for the same reason enlarging on screen loses sharpness.

Troubleshooting: why a resize didn't come out the way you expected

A handful of specific symptoms account for most confusion when resizing a photo, and each one has a concrete cause.

• The photo looks stretched or squashed: aspect ratio lock was off, or a preset with a different ratio than the original was applied on top of a photo that wasn't cropped to match first.
• The photo looks blurry after resizing: the target size is larger than the original, which always requires the browser to invent pixels that weren't captured (see "Resizing up versus resizing down" above).
• A transparent background turned solid white: the output format was set to JPG, which has no transparency channel at all; switch to PNG to keep transparent areas transparent.
• The downloaded file is much larger than expected: the format was set to PNG (lossless, so file size scales with image complexity rather than a quality slider) instead of JPG.
• The colors look slightly different after resizing: this is usually the source photo's own color profile being handled differently by the display, not something the resize itself changed, since resizing only recomputes pixel positions, not color values.

What this tool does not do

Being upfront about scope: this is a resizer, not a full photo editor. It changes a photo's pixel dimensions and, optionally, its file format and compression quality; it does not crop, rotate, add filters, remove backgrounds, or edit content within the photo. It also does not do AI upscaling (inventing new detail to enlarge a low resolution source cleanly): a large enlargement will look soft, for the reasons explained above, rather than magically sharp. And because it works entirely from the pixels already in your photo, it can't recover detail lost to an earlier, aggressive compression pass; a heavily compressed source will still show its original compression artifacts after resizing, just at a different size.