Outilo Outilo

Resize an image

Resize images in batch (percentage or pixels), keep aspect ratio, convert to WebP/JPG/PNG and download as ZIP. 100% browser, no upload.

Drag your images here or select them

Supports PNG, JPEG and WebP. Multi-files allowed.

Imported files

No image pending

Drop one or more visuals above to start configuring your resize.

Settings

Configure your target dimensions below.

Resize mode
Desired output size
Image scale

Keep aspect ratio

Automatically adjusts dimensions to avoid stretching your visuals.

Enable conversion
Image quality
WebP advantage: reduces weight by ~30% more than JPEG with no perceptible visual loss. Recommended quality: 80% to 85% for an excellent weight/sharpness ratio.
Optimization complete

Get your resized images

Overall weight has been optimized for the web.

Images processed
Original size
New size
Saved space

Previews & individual downloads

Yoann Begue
Edited by Outilo Reviewed by Yoann Begue Last verified on 28/05/2026

Go deeper

An image resizer built for a fast web

A smartphone photo easily weighs 4 to 8 MB and is 4000 pixels wide. That's way too much for a website, an email or an online form. Our image resizer adjusts your visuals to the right dimension — by percentage or by precise pixels — to gain loading speed, save bandwidth and boost your SEO. Everything runs directly in your browser, no byte ever sent to our servers.

100% private

Your images never leave your device. Processing uses the browser's native HTML5 APIs.

Batch processing

Drop 1 or 50 files at once. Web Workers parallelize resizing so the UI never freezes.

ZIP export

Grab all resized images in a single ZIP file, ready to drop on your website or drive.

Two modes for two use cases: percentage or precise pixels

The Percentage mode is ideal when you simply want to "lighten" a batch of photos without doing the math: 50% smaller halves the dimensions and divides the weight by about four. The Precise Pixels mode meets exact constraints (1200 px wide for a blog, 800×600 for a product sheet, 1080 px for Instagram). The aspect ratio lock automatically computes the missing dimension to never stretch your visuals.

Web dimension best practices

  • Blog article: 1200 to 1600 px wide is more than enough.
  • Thumbnail: 400 to 600 px wide.
  • Profile picture: 400×400 px or 512×512 px.
  • Social banner: 1500×500 px (Twitter/X), 1640×856 px (Facebook).
  • Email attachment: 1000 px max and aim for under 500 KB per image.

Bonus: format conversion and compression

Optionally, you can convert your files to WebP (Google's recommended standard, about 30% lighter than JPEG with no visible loss), JPEG or PNG, and tune quality from 10 to 100%. Handy to turn a heavy PNG into a light WebP, or to fit a JPEG photo under a strict weight cap.

Built-in safeguards

  • Do not upscale: blocks upscaling a small image, which would only add blur.
  • Strip metadata (EXIF): removes GPS coordinates, camera model and date to protect your privacy and lighten the file.
  • Swap width / height: flip from landscape to portrait in one click without retyping values.

FAQ

Are my images sent to a server?

No. The tool is designed to process images directly in your browser. Your files stay on your device while resizing.

What is the difference between resizing, cropping and compressing an image?

Resizing changes the width and height in pixels. Cropping cuts part of the image. Compressing reduces file size without necessarily changing its dimensions.

How do I avoid distorting an image?

Keep the width-to-height aspect ratio. In practice, change only the width or the height, then let the other dimension be calculated automatically.

Can I resize several images at once?

Yes. The tool lets you import multiple images, apply the same settings, then download the files individually or as a ZIP archive.

Which format should I choose after resizing?

For photos, JPG is often suitable. For images with transparency, use PNG. For the web, WebP often offers a good balance between quality and file size.

Why should I avoid enlarging a small image?

Enlarging an image does not create real detail. The result can become blurry, pixelated or heavier without being sharper.

What size should I choose for a web image?

For a large content image, a width of 1200 to 1600 pixels is often enough. For a thumbnail, 300 to 600 pixels may be enough. The right choice depends on the actual display size on the page.

Does resizing an image also reduce its file size?

Often yes, because an image with fewer pixels contains less data. But the final file size also depends on the selected format and compression level.

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