--- title: "Image Resizer - Resize images to custom dimensions" description: "Resize JPEG, PNG, GIF, and WebP images to custom dimensions. You can set width and height in pixels or percentages and keep the aspect ratio while resizing." canonical_url: "https://web-toolbox.dev/en/tools/image-resizer" meta: author: K "og:description": "Resize JPEG, PNG, GIF, and WebP images to custom dimensions. You can set width and height in pixels or percentages and keep the aspect ratio while resizing." "og:image": "https://web-toolbox.dev/og/en/tools/image-resizer-7a213165.png" "og:image:alt": "Image Resizer" "og:image:height": "630" "og:image:width": "1200" "og:title": "Image Resizer - Resize images to custom dimensions" --- > Index of every page on this site: [llms.txt](https://web-toolbox.dev/llms.txt) # **Image Resizer** Resize images while maintaining aspect ratio **Image File** **Drop image here**or click to select an image Supports JPEG, PNG, GIF, and WebP. All processing is done securely in your browser and never uploaded to a server. ## What is Image Resizer? Image Resizer is a browser-based tool for resizing JPEG, PNG, GIF, and WebP images. You can set the size in pixels or percentages, then compare the resized result and file size before downloading. All processing happens locally in the browser, so the image is not uploaded to a server. It works well for preparing blog images, adjusting graphics for social media, or reducing file sizes for sharing. ## How to Use Image Resizer 1. Drag and drop an image, or click to select one. 2. Choose whether to resize by pixels or percentage. 3. Adjust the width and height, or choose a scale percentage. 4. Review the preview and file size, then download the result if it looks right. The preview updates in real time whenever you change the settings. ## Main Settings ### Size Mode The tool supports both pixel-based resizing and percentage-based resizing. #### Resize by Pixels This mode lets you enter exact width and height values. It is useful when you need specific dimensions, such as setting a blog image to 800px wide or matching a platform's recommended size. #### Resize by Percentage This mode scales the image relative to its original size. Options such as 25%, 50%, 75%, 150%, and 200% make it easy to shrink or enlarge an image without entering exact numbers. ### Lock Aspect Ratio When aspect ratio is locked, images resize while maintaining their original proportions. Changing the width automatically adjusts the height, preventing distortion. When unlocked, you can set width and height independently. However, using values that differ from the original aspect ratio may stretch or compress the image. ### Preview and File Size The tool shows the original and resized dimensions, previews, and file sizes side by side. This makes it easier to notice when you have resized too aggressively or enlarged the image too far. ## Use Cases - Resizing blog or website images to a consistent width - Adjusting images to better fit social media post sizes - Shrinking large photos before sending them by email or sharing them - Comparing the original and resized result before downloading ## Things to Keep in Mind - Enlarging an image beyond its original size can make it look soft or pixelated - Turning off the aspect ratio lock can distort the image - The tool processes one image at a time - Supported formats are JPEG, PNG, GIF, and WebP When enlarging an image, it is a good idea to check the preview carefully before downloading. ## Technical Information This tool runs entirely in the browser, and the image is not uploaded to a server. You can compare the original and resized results locally before saving the file. **How was your experience?** Last updated: October 30, 2025 ### **Related Tools** - [

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](https://web-toolbox.dev/en/tools/svg-blob-generator) ```json {"@context":"https://schema.org","@graph":[{"@id":"https://web-toolbox.dev/en#website","@type":"WebSite","description":"アカウント登録不要で使える無料Web開発ツール80種類以上。JSON整形、Base64変換、カラーコード変換、QRコード生成などをブラウザ上で瞬時に実行。開発者の作業効率を大幅に向上させます。","inLanguage":"en-US","name":"Web ToolBox","url":"https://web-toolbox.dev/en","translationOfWork":{"@id":"https://web-toolbox.dev/#website"}},{"@id":"https://web-toolbox.dev/en/tools/image-resizer#webpage","@type":"WebPage","description":"Resize JPEG, PNG, GIF, and WebP images to custom dimensions. You can set width and height in pixels or percentages and keep the aspect ratio while resizing.","name":"Image Resizer - Resize images to custom dimensions","url":"https://web-toolbox.dev/en/tools/image-resizer","isPartOf":{"@id":"https://web-toolbox.dev/en#website"},"potentialAction":[{"@type":"ReadAction","target":["https://web-toolbox.dev/en/tools/image-resizer"]}]},{"@id":"https://web-toolbox.dev/en/tools/image-resizer#/schema/web-application/1","@type":"WebApplication","applicationCategory":"UtilityApplication","description":"Resize JPEG, PNG, GIF, and WebP images to custom dimensions. You can set width and height in pixels or percentages and keep the aspect ratio while resizing.","name":"Image Resizer - Resize images to custom dimensions","operatingSystem":"Windows, macOS, Linux, Android, iOS"}]} ``` ## Sitemap See the full [sitemap](https://web-toolbox.dev/sitemap.md) for all pages.