Resize an Image Online

Resizing an image just means changing its width and height in pixels. You do it constantly — a 4000-pixel-wide phone photo is far too big for a website, a profile picture needs to be square, and almost every exam or visa portal demands an exact pixel size. This guide covers how to resize cleanly, how to avoid the one mistake that makes images look bad, and the right dimensions for the things people resize for most.

Resize by dimensions or by percentage

There are two ways to think about a resize:

• By dimensions — you know the exact pixels you need (say 1920 × 1080 for a wallpaper, or 600 × 600 for a US passport photo). Type the width and height and you’re done.
• By percentage — you just want the image smaller (or larger) without caring about the precise numbers. Scaling to 50% halves both sides; 200% doubles them.

Both reach the same place; pick whichever matches what you already know. With the tool above, By dimensions is the default, and a percentage mode is one tap away.

Keep the aspect ratio locked (usually)

The aspect ratio is the relationship between width and height. Lock it and the image scales proportionally — set the width and the height follows automatically, so nothing looks stretched. This is what you want 99% of the time.

Unlock it only when a target demands an exact shape that differs from your image — for example squeezing a landscape photo into a square avatar. In that case, consider cropping to the shape first, then resizing, so the subject isn’t distorted.

The one rule: don’t upscale

Making an image smaller is effectively lossless to the eye — it stays sharp. Making it larger than the original is the trap: there’s no extra detail to show, so the result looks soft and mushy. Software “upscaling” can guess at detail, but a plain resize cannot.

The fix is simple: always start from the largest original you have. If you need a 1080-pixel image, don’t take a 400-pixel thumbnail and blow it up — find the full-resolution copy. The tool flags it when your target is bigger than the source so you’re never surprised.

Resizing vs. cropping vs. compressing

These three get confused constantly:

• Resize — scale the whole image to new dimensions.
• Crop — cut away part of the image to change its framing or shape.
• Compress — shrink the file size (KB/MB) by changing encoding, without necessarily changing dimensions.

They stack nicely. A common workflow for a form that wants “200 × 230 px, under 50 KB” is: resize to 200 × 230, then compress to land under 50 KB. We have dedicated tools for each.

Common sizes worth knowing

Social media (use the preset picker for the full list):

• Instagram post 1080 × 1080, portrait 1080 × 1350, story/reel 1080 × 1920
• YouTube thumbnail 1280 × 720, channel banner 2560 × 1440
• Facebook cover 851 × 315, X (Twitter) header 1500 × 500, LinkedIn banner 1584 × 396

Official / exam photos (India and beyond) — these often specify both a pixel size and a KB cap:

• India passport 630 × 810, UPSC 350 × 350, bank exams (IBPS/SBI) 200 × 230, NEET 180 × 252
• US passport/visa 600 × 600, UK passport 600 × 750

Pick the matching preset above and the dimensions are filled in for you. For the KB limits, resize first and finish in the compressor.

Choosing a format

Leave the format on Auto to keep your original type (PNG stays PNG, JPG stays JPG, WebP stays WebP) — resizing shouldn’t silently change your file type. Override it when you have a reason: JPEG for the smallest photos, WebP for small files that keep transparency, PNG for crisp graphics, logos, and screenshots.

As a bonus, re-encoding during a resize strips EXIF/GPS metadata, so the location and camera details baked into phone photos don’t travel with the smaller copy.