Image Resizer

Resize images by pixels or percentage. Maintains aspect ratio.

100% Private — Your files never leave your device.

All processing happens in your browser. Nothing is uploaded to any server.

Drop a file here or click to browse

Supports: JPG, PNG, WebP, SVG

Max 50MB per file

Upload an image to resize it

Preview appears here instantly

How it works

When to Resize Images

Common reasons to resize images:

Web optimization: A 4000px-wide photo is overkill for a website that displays it at 800px. Resize to the display size to save bandwidth.
Social media: Each platform has optimal dimensions. Uploading the right size prevents unwanted cropping.
Email attachments: Many email providers limit attachment size to 25MB. Resizing large photos makes them email-friendly.
Print preparation: Photos for print need specific dimensions at 300 DPI.

How It Works

Our resizer uses the browser’s Canvas API to re-draw your image at the new dimensions. The process is entirely local — your image never leaves your device.

Upload an image (JPG, PNG, WebP, or SVG)
Set target dimensions in pixels or use a percentage preset
Toggle aspect ratio lock on or off
Download the resized result as PNG

Common Size Presets

Use Case	Recommended Size
Website hero image	1920 × 1080px
Blog post image	1200 × 800px
Email header	600 × 200px
Thumbnail	300 × 300px
Social media profile	400 × 400px
Print (4×6 at 300 DPI)	1800 × 1200px

Tips

Always resize down, not up. Enlarging a small image creates blurry results.
Use percentage presets (25%, 50%, 75%) for quick resizing when exact dimensions don’t matter.
Combine with compression: After resizing, use our Image Compressor to further reduce file size.

Real-World Examples

Instagram-ready profile photo

Width: 1,080 Height: 1,080 Keep Aspect Ratio: off

A social media manager needs a 1080×1080px square crop for Instagram. The original headshot is 4000×2700px. With aspect ratio unlocked, they set 1080×1080 to get the exact dimensions Instagram requires. File drops from 5MB to 800KB as a bonus.

Website hero image for Retina

Width: 1,920 Height: 1,080 Keep Aspect Ratio: on

A web developer resizes a 6000×4000px stock photo to 1920px wide for a website hero banner. With aspect ratio locked, height auto-calculates to 1280px. The resized image loads 3× faster while still looking sharp on Retina displays.

Batch thumbnails at 25%

Percentage: 25 Keep Aspect Ratio: on

A photographer needs 300×200px thumbnails from 1200×800px originals. Using the 25% preset, all images resize proportionally in one click. Each thumbnail is under 50KB — perfect for a gallery grid that loads instantly.

Frequently Asked Questions

What's the difference between resizing and compressing an image?

Resizing changes the pixel dimensions of an image (e.g., from 4000×3000 to 1920×1440). Compressing reduces file size by lowering quality without changing dimensions. For the smallest file size, resize first then compress — a 1920px-wide image compressed at 80% will be much smaller than a 4000px-wide image compressed at 80%.

Will resizing my image reduce its quality?

Downscaling (making smaller) generally looks fine because you're discarding excess pixels. Upscaling (making larger) can look blurry because the browser has to invent new pixels through interpolation. As a rule, never upscale more than 150% of the original size.

What size should I use for social media?

Recommended sizes as of 2025: Instagram posts: 1080×1080px (square) or 1080×1350px (portrait). Facebook: 1200×630px. Twitter/X: 1200×675px. LinkedIn: 1200×627px. YouTube thumbnails: 1280×720px. These are optimal — platforms will accept other sizes but may crop or compress them.

What does 'maintain aspect ratio' mean?

Aspect ratio is the proportional relationship between width and height. A 4000×3000 image has a 4:3 aspect ratio. When 'maintain aspect ratio' is on, changing the width automatically adjusts the height (and vice versa) to keep the image from stretching or squishing. Turn it off only if you intentionally want to distort the proportions.

What's the maximum image size I can resize?

Browser Canvas API supports images up to approximately 16,384×16,384 pixels on most devices. For practical purposes, images up to 8000×8000px resize smoothly. Very large images (20MP+ photos) may be slow on older devices but will still work.

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