Image Resizer

How to resize an image

Upload your image, then either enter an exact width and height in pixels, or drag the percentage slider to scale it up or down. With "Lock aspect ratio" checked, changing the width automatically adjusts the height to match the original proportions, so your image never looks stretched or squashed.

Common sizes you'll need to hit

Most resizing needs come down to a handful of real-world limits. A Facebook cover photo displays best at 820312px, an Instagram square post at 10801080px, and a YouTube thumbnail at 1280720px. Email attachment limits are usually 25MB total (Gmail) or 20MB (Outlook), so a single oversized photo straight off a phone often 12+ megapixels can eat most of that budget before you've added a second image. Many website upload forms and content management systems cap image dimensions too, commonly rejecting anything wider than 2000-2500px to keep page load times reasonable. Resizing down to the platform's actual display size, instead of uploading the original, keeps quality consistent and file sizes small.

Aspect ratio, and why locking it matters

Aspect ratio is the relationship between an image's width and height a 4:3 photo and a 16:9 photo show the same scene cropped differently. Changing width and height independently without locking the ratio stretches or squishes the image, distorting faces and straight lines in an obvious way. Locking the ratio keeps every dimension change proportional to the original, which is why it's checked by default here.

Enlarging vs. shrinking

Shrinking a photo throws away pixels and generally looks clean at any reasonable size. Enlarging goes the other direction the tool has to invent new pixel data that was never captured, which is why images stretched much beyond their original size look soft, blurry, or blocky. As a rule of thumb, avoid scaling up by more than about 25-50% if you want the result to look sharp.

FAQ

Will resizing reduce image quality?
Shrinking usually looks fine since you're removing detail rather than inventing it. Enlarging beyond the original size can look soft or blurry because no new detail is added the tool can only stretch existing pixels.

Is my image uploaded anywhere?
No everything happens locally in your browser using the HTML canvas element. Your image is decoded and redrawn entirely on your device and is never sent to a server.

What image dimensions do popular platforms need?
It varies by platform and placement. Common targets include 10801080px for an Instagram square post, 1200630px for a Facebook or LinkedIn link preview image, and 1280720px for a YouTube thumbnail.

Can I make an image bigger than its original size?
Yes, the percentage slider goes up to 200%, but enlarging doesn't add real detail it stretches existing pixels, so results look softer the further past 100% you go.

What's the difference between resizing by pixels and by percentage?
Entering exact width and height in pixels is best when a platform or form specifies precise dimensions. The percentage slider is faster when you just want to scale an image up or down proportionally without doing the math yourself.