Image Resizer

📖 Tool Introduction

Image Resizer is a completely free, instant-use online tool for adjusting the dimensions and file size of pictures right inside your browser, with no software to install. It supports precise resizing to a target width and height, one-click percentage scaling, and an aspect-ratio lock that keeps the original proportions so your image is never distorted. Once processed, you can preview the result immediately and download it as PNG or JPEG. Whether you are compressing images for a website, fitting cover art to a social platform, or standardising a batch of assets, this tool handles it with ease. Every operation happens locally in your browser — your pictures are never uploaded to any server, so your privacy is fully protected. The interface is clean and intuitive, supporting both drag-and-drop and click-to-select upload, and is compatible with common formats such as PNG, JPEG and WebP. It is available in Simplified Chinese, Traditional Chinese and English, automatically follows the website theme colour and corner-radius style, and works smoothly on desktop and mobile. No registration and no installation are required — just open it and drop an image. Image Resizer is a practical everyday companion for designers, content operators and individual users alike. The whole workflow — upload, set the target size, resize, download — takes only a few seconds, and because the processing is completely offline it works reliably even on weak connections and in environments where uploading images is not allowed. The tool stores nothing: there is no account, no history and no tracking, so sensitive graphics such as internal documents, drafts and personal photos can be handled with complete peace of mind while you keep full control over every file that leaves your device.

✨ Key Features

• Precise resizing: output an image at exactly the target width and height you specify
• Percentage scaling: resize to 25%, 50% or 75% in one click, or enter a custom ratio
• Aspect-ratio lock: tick the box, fill in only one side, and the image scales proportionally without distortion
• Format choice: export as PNG or JPEG to suit different use cases
• Live preview: original and new dimensions plus file sizes are shown at a glance, what you see is what you get
• Fully local: your image never leaves the browser — zero uploads, zero leaks

📝 How to Use

1. Click the upload area to choose an image, or simply drag and drop one onto it
2. Enter the target width and height in pixels
3. For proportional scaling, tick Keep aspect ratio and fill in only one side
4. Pick the output format and an optional percentage, then click Resize
5. Check the preview and click Download image to save the result

⚠️ Notes

• Format support: PNG, JPEG, WebP, BMP and the first frame of GIF are supported; other formats may fail to decode
• Very large images: extremely large pictures are best compressed before upload to avoid heavy browser memory usage
• Aspect lock behaviour: when locked and both sides are filled in, the image scales to fit the filled dimensions proportionally
• JPEG quality: JPEG export is lossy, so complex images may lose slight detail
• Original stays safe: processing never overwrites or modifies the original file on your device