Image Resizer & Converter
Resize images by pixels or percentage online. Convert between JPEG, PNG, and WebP with quality control. Aspect ratio lock, common size presets, live preview. No upload — 100% private, runs entirely in your browser.
Drop image or click to upload
JPEG · PNG · WebP · GIF · Paste with Ctrl+V · Max 20 MB
How to resize an image online
Upload your image by dragging it onto the upload zone, clicking to browse files, or pasting directly from your clipboard with Ctrl+V.
Switch between Pixels mode to set exact width and height, or Percentage mode to scale up or down relative to the original. Use a size preset — HD, Square, OG Image, YouTube Thumbnail — for common dimensions in one click.
Choose your output format (JPEG, PNG, or WebP) and quality level, then click Resize & Convert. Preview the output with file size comparison, then download your resized image.
Pixels vs percentage: which mode to use
Pixel mode is best when you need a specific output size — for example, a 1200×630 Open Graph image, a 400×400 avatar, or a 1920×1080 wallpaper. Enter your target dimensions directly and the tool handles the math.
Percentage mode is best when you want to scale relative to the original without needing to know the exact pixel dimensions. At 50% the image is halved in both dimensions (quarter the file size). At 200% it is doubled.
Common image sizes for web and social
- Open Graph / Facebook share: 1200 × 630 px
- Twitter / X card: 1200 × 675 px
- YouTube thumbnail: 1280 × 720 px
- Instagram square: 1080 × 1080 px
- Instagram portrait: 1080 × 1350 px
- Full HD desktop: 1920 × 1080 px
- Blog hero: 1200 × 628 px
- Product image (e-commerce): 800 × 800 px
- Avatar / profile photo: 400 × 400 px
- Thumbnail: 300 × 300 px
Which output format should you choose?
WebP is the modern standard for the web. It produces files 25–35% smaller than JPEG at the same quality level and supports transparency like PNG. All modern browsers support it — use WebP for blog images, product photos, and any image you are optimising for page speed.
JPEG is the safest choice for maximum compatibility: email clients, older CMS platforms, and some social media platforms still process JPEG most reliably. Use the quality slider at 80–85% for web delivery.
PNG is lossless — the quality slider has no effect on file size. Use it for logos, icons, screenshots, or images with transparency when WebP is not an option. PNG files are typically 3–5× larger than equivalent WebP.
Features
- Pixel mode — set exact width and height in pixels
- Percentage mode — scale from 1% to 200%
- Common size presets — HD, Square, OG Image, YouTube Thumbnail and more
- Aspect ratio lock — auto-calculates the missing dimension
- Format conversion — JPEG, PNG, WebP output
- Quality slider for JPEG and WebP (10–100%)
- Live output preview with file size comparison
- Drag-and-drop, file picker, paste (Ctrl+V)
- 100% private — images never leave your browser
Frequently asked questions
How do I resize an image to specific pixels?
Switch to Pixels mode, enter your target width and height, and click Resize & Convert. If aspect ratio lock is on, changing the width automatically updates the height to keep proportions. Uncheck the lock to set width and height independently.
How do I resize an image by percentage?
Switch to Percentage mode and drag the slider or type a value between 1% and 200%. At 50% the image is halved in both dimensions (resulting in a quarter of the original pixel count). At 200% it is doubled. The resulting pixel dimensions are shown in real time.
What is the difference between resizing and cropping?
Resizing scales the entire image to new dimensions — nothing is cut away. Cropping removes the edges to change the framing or aspect ratio. To crop, use the Image Cropper tool. To resize after cropping, use this resizer.
What output format should I use?
WebP is recommended for most web images — it is 25–35% smaller than JPEG at the same quality and supports transparency. Use JPEG for photographs that need broad compatibility (email, social). Use PNG when you need lossless quality or transparency and WebP is not an option.
Does resizing preserve the aspect ratio?
Yes, by default. The aspect ratio lock is enabled: changing the width automatically recalculates the height (and vice versa) to maintain proportions. Uncheck "Maintain aspect ratio" to set width and height independently.
Are my images uploaded to a server?
No. All resizing happens entirely in your browser using the Canvas API. Your images never leave your device and are never uploaded to any server. The tool works completely offline after the page loads.
What is the maximum file size supported?
Files up to 20 MB are supported. Images above this limit may cause the browser to run out of memory during Canvas processing. If you need to process a very large image, resize it in a desktop image editor first, then use this tool for format conversion.