What is Image Resizer?

The Image Resizer scales images to exact pixel dimensions or by percentage. Lock the aspect ratio to prevent distortion, or unlock it for custom sizing. Works well for websites, email signatures, and any size you need.

Resizing uses high-quality canvas smoothing — closer to bicubic than nearest-neighbour — so the output stays sharp when scaling up and clean when scaling down. The percentage slider goes from 1% to 500% and the width and height fields accept any integer up to your device's memory limit. One-click presets jump straight to Instagram, Facebook, X, LinkedIn, YouTube, Pinterest, and Open Graph dimensions. Rotate sideways phone photos in 90° steps or flip them horizontally and vertically before resizing. Pick Stretch to fill for an exact fit, or Fit inside to scale without distortion and pad the gaps with a colour you choose (or transparency for PNG and WebP). Choose PNG (lossless), JPEG, or WebP for output, with a quality slider for the lossy formats. Set a target file size in KB and the tool searches for the quality that hits it. A live size estimate appears under the controls so you know before you click Download. Toggle Compare to see the original and resized images side by side at the same width, or copy the result straight to your clipboard to paste it without saving a file.

How to use

1. Step 1 — Add your image by dropping it onto the upload area, clicking to browse, or pasting a copied screenshot with Ctrl + V.
2. Step 2 — Enter the desired width and/or height in pixels, or use the percentage slider. Toggle the lock icon to maintain or unlock the aspect ratio.
3. Step 3 — Choose your output format (PNG, JPEG, or WebP) and adjust quality for lossy formats. Optionally set a target file size in KB to auto-tune quality. Click Download to save.

When to use

• Shrinking a 4000 px camera photo to 1200 px before uploading to a blog or email.
• Matching the exact pixel dimensions a marketplace or print shop demands for product photos.
• Halving a screenshot for documentation pages where the original is too wide for the layout.

Result

A 4000x3000 photo needs to be 800px wide for a blog post. Enter 800 for width with aspect ratio locked — height auto-calculates to 600. The 12MP image is now perfectly sized for web use.

FAQ

Does scaling down lose detail permanently?

Yes. When you shrink an image and save it, the discarded pixels are gone. Always keep the original file separately. The tool itself never overwrites your source — the resized version downloads as a new file.

Can I make a small image bigger without it looking blurry?

Only partly. Scaling up to about 150% still looks reasonable. Beyond that the canvas smoother starts inventing pixels and edges get soft. For true upscaling, AI tools like Real-ESRGAN do a better job than any pure resampling.

What does locking the aspect ratio actually do?

When locked, changing the width automatically calculates the matching height, so circles stay circular and faces stay normal. Unlock it only when you deliberately want a stretched or squashed look. If you need an exact canvas size but can't accept distortion, switch the Sizing toggle to Fit inside — it scales the image to fit and pads the leftover space instead of stretching.

What's the difference between resizing by pixels and by percentage?

Pixels target an exact final size, useful when a site demands 1200x630 for OG images. Percentage scales relative to the original, useful when you want to halve a folder of photos without thinking about exact numbers each time.

Can I choose the output format and quality?

Yes. Pick PNG, JPEG, or WebP from the Format dropdown — input type no longer dictates output. For JPEG and WebP a Quality slider (1–100) appears so you can balance size and sharpness. Filename gets the new dimensions appended. EXIF metadata is not preserved.

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