What does 'lock aspect ratio' do?

With it on, typing a width fills in the matching height automatically (and vice versa), so the picture never looks stretched or squashed. Turn it off if you deliberately want a different aspect ratio.

Can I make an image bigger, not just smaller?

Yes — enter dimensions or a percentage larger than the original. Enlarging a photo beyond its real resolution will look softer, since no new detail is created.

Can I resize multiple images at once?

Yes — upload as many as you like. The same dimensions or percentage are applied to each one, computed from its own original size, and they're packaged into a single ZIP.

Is my image uploaded anywhere?

No. Everything happens inside your browser, so your images never leave your device.

How does the social media preset pick the exact size?

By default it fills the whole box and crops whatever doesn't fit, so a 170×170 Facebook profile picture request always comes back exactly 170×170 — never smaller. Turn on "Fit without cropping" to instead shrink the photo to fit entirely inside the box, padding any leftover space (transparent for PNG/WebP, white for JPG) rather than cutting anything off.

Resize Images Online

Resize a JPG, PNG, or WebP image by exact dimensions, percentage, or a social media preset.

Drag & drop Image files here

or browse

No server-imposed limits · free

Resize by

Percentage of original size%

Resize Image changes a picture's pixel dimensions by exact width and height, by percentage, or to a social-media preset. The format never changes — a JPG stays a JPG, a PNG keeps its transparency and a WebP stays a WebP. Lock the aspect ratio so a photo is never stretched; presets fill the exact box, cropping what doesn't fit, so a 170×170 profile picture always comes back 170×170.

What you can do

Three ways to size: Exact dimensions, Percentage, or Social media presets.
Lock aspect ratio so photos never look stretched or squashed.
Make images bigger as well as smaller (enlarging can't add detail that was never there).
Batch: the same dimensions or percentage is applied to each image from its own original size, in one ZIP.

How it works

1Drop your JPG, PNG or WebP images onto the page.
2Under Resize by, choose Exact dimensions, Percentage or Social media.
3Enter the size you need, or pick a Platform preset.
4Click Process File, then Download.

Why use SmilingPDF for this

Format and transparency are preserved exactly.
Social-media presets always return the exact size you asked for.
Everything runs on your device — your images are never uploaded.

Private by design

Your file stays on your device.

No upload
No server storage
No account required
Browser-based processing
No watermark

This tool runs inside your browser tab. Your file is read from your device, processed there, and handed back as a download — it is never sent to a SmilingPDF server, so there is nothing for us to store, read, or lose. You can check for yourself: open your browser's developer tools, switch to the Network tab and run the tool. Like most sites, SmilingPDF uses Google Analytics to count visits and which tools are used; that never includes the contents of your files. The privacy policy lists everything the site does collect.