Photo Resizer
Resize and convert a photo in your browser. Pick a width, a height, a format and a quality; the tool does the work on your device without uploading anything.
Explain like I'm 5 (what even is this calculator?)
You drop a photo in. You say how big you want it and what format. The tool makes a new, smaller version of that photo, right there in the page. You can save the new file. The original is untouched, and the file is never sent anywhere.
Resize
Prove it
Resizing is done by drawing the source image onto an HTML5 canvas at the target dimensions, then calling canvas.toBlob() with the chosen format and quality. All in your browser, no network calls.
Useful? Save this calculator: press Ctrl + D to bookmark it.
How to choose sensible dimensions
The right size for a photo depends entirely on where it is going to live. A profile picture on a social network does not need to be 4000 pixels wide. A hero image on a website rarely needs to be bigger than 2000 pixels on the long edge. Email attachments should almost never exceed 1600 pixels, or roughly 500 KB.
- Profile pictures: 400×400 px is plenty. Most platforms will scale down to 200×200 anyway.
- Social posts and messaging: 1080×1080 for square, 1080×1350 for portrait. Anything larger gets re-compressed by the platform and looks worse, not better.
- Web banners and blog images: 1600×900 for standard landscape, 2400×1600 for high-DPI "retina" displays.
- Printing 6×4 inches at 300 DPI: 1800×1200 pixels.
- Email attachment: under 1600 pixels on the long edge, JPEG quality 70-80.
JPEG vs PNG vs WebP, briefly
JPEG is the oldest of the three. It uses lossy compression that is very good at photos, less good at line art, text and flat colours. For a holiday photo at quality 85, JPEG usually wins.
PNG is lossless. The pixel values you put in are the pixel values you get out. That makes PNG ideal for screenshots, diagrams, logos, and anything with hard edges or text. The price is bigger files for photographic content.
WebP is Google's modern format, supported in every current browser. It usually gives you JPEG-like quality at 25-35% smaller file sizes, or PNG-like lossless compression at noticeably smaller sizes. If you do not need to open the file in very old software, WebP is usually the best default for the web.
Why a browser-only tool
Every other "free online photo resizer" uploads your file to someone else's server. Maybe that is fine. Maybe the file is a pet photo. Maybe it is a passport scan, a child's face, or a confidential product shot. The safe default is to never send the image in the first place. That is all this tool does: the entire resize happens in your own browser tab, using the standard Canvas API. You can check with your browser's developer tools; there are no network requests when you press Resize.
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Frequently asked questions
Does the Photo Resizer upload my image anywhere?
No. The image is decoded, resized, and re-encoded entirely in your browser using an HTML canvas. Nothing is uploaded, stored, or logged. You could disconnect from the internet mid-resize and it would still work.
Which image formats does it support?
JPEG, PNG, and WebP for both input and output. You can convert between them: for example, a large PNG screenshot can be saved as a much smaller JPEG or WebP.
What does the quality slider do?
For JPEG and WebP, quality controls how aggressively the image is compressed. Higher values produce bigger, sharper files. Lower values produce smaller files with more visible compression artefacts. Quality has no effect on PNG because PNG is a lossless format.
What is the biggest image I can resize?
Whatever your browser and device can hold in memory. For most modern phones and laptops, up to around 100 megapixels is fine. Very large images may slow the browser tab down briefly while the canvas renders.
Does this work on phones?
Yes. All modern mobile browsers (iOS Safari, Chrome, Firefox, Samsung Internet) support the Canvas API used here.