Convert - Resize - Rename - Compare - WebP - AVIF - JPEG - PNG
Drop images here or click to browse
JPG - PNG - GIF - AVIF - WEBP - BMP - SVG
Ctrl+V to paste from clipboard
Drag slider - Arrow keys - Shift+Arrow x10
About This Image Converter
This is a free, browser-based image converter that runs entirely on your device. No files are uploaded to any server - conversion happens locally using the HTML5 Canvas API, which means your images stay private and the tool works offline once the page has loaded.
It supports converting JPG, PNG, GIF, BMP, SVG, and AVIF files to WebP, AVIF, JPEG, or PNG output. You can convert a single image or batch-process dozens at once, download them individually, or grab everything as a ZIP archive.
Features
Batch Conversion
Drop multiple images at once. All files convert in parallel and can be downloaded together as a ZIP.
WebP & AVIF Output
Export to modern formats that reduce file sizes by 25-80% compared to JPEG, without visible quality loss.
Per-Image Resize
Set a target width or height for each image individually. Aspect ratio is locked per image, so a portrait and landscape image both scale correctly.
Quality Control
Use the global quality slider for a quick batch, or open the Re-convert panel on any card to set a different quality for that specific image.
Before / After Compare
A draggable split-screen slider lets you inspect the original against the converted output side by side. Expand to full screen for a closer look.
Rename Before Download
Click the edit button on any card to rename the file before downloading. The new name is also used inside the ZIP.
Auto-retry Logic
When a conversion produces a file larger than the original, the tool automatically retries at a lower quality until the output is smaller.
Lossless Mode
Enable lossless compression for WebP and PNG to get pixel-perfect output with no quality degradation whatsoever.
Clipboard Paste
Press Ctrl+V anywhere on the page to paste an image directly from your clipboard into the queue.
How to Use
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Add your images
Drag and drop image files onto the upload area, click it to browse, or press Ctrl+V to paste from clipboard. Duplicate files are automatically skipped.
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Choose an output format and quality
Select WebP, AVIF, JPEG, or PNG from the format dropdown. Adjust the quality slider (85 is a good starting point for most photos). Enable Lossless if you need exact pixel accuracy.
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Optionally resize
Enable Global Resize and enter a target width or height. With aspect ratio lock on, you only need one dimension - each image calculates the other from its own aspect ratio. For a specific image, use the Resize button on its card instead.
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Review the results
Each card shows the output size, savings percentage, actual quality used, and conversion time. Click Compare to open the before/after slider, or Full for a full-screen view.
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Download
Download each image individually with its card's Download button, or click ZIP All to get every converted image in a single archive.
Choosing the Right Output Format
The best format depends on what you are optimising for - file size, browser support, or lossless fidelity.
| Format | Typical size vs JPEG | Best for | Browser support |
|---|---|---|---|
| WebP | 25-35% smaller recommended | Web images, blog photos, thumbnails | All modern browsers, Chrome, Firefox, Safari 14+ |
| AVIF | 40-55% smaller | High-quality photos where maximum compression matters | Chrome 85+, Firefox 93+, Safari 16+ |
| JPEG | Baseline | Photographs shared outside the web, email attachments | Universal |
| PNG | Larger, lossless | Screenshots, logos, images with transparency or text | Universal |
For most blog images and web thumbnails, WebP at quality 80-90 is the right choice. AVIF gives better compression but conversion is slower and browser support is slightly narrower. Use PNG when you need transparency or when pixel-perfect accuracy is required.
Frequently Asked Questions
No. All conversion happens entirely in your browser using the HTML5 Canvas API. Your images are never sent to any server. This also means the tool works without an internet connection once the page has loaded.
On average, WebP at equivalent quality is 25-35% smaller than JPEG and 25-45% smaller than PNG. The savings vary by image content - photos with lots of detail compress better than flat graphics. The tool shows the exact savings percentage on each card after conversion.
For web images, 80-85 is a good balance between file size and visual quality. For hero images or featured photos where quality is critical, use 90-95. Below 70, compression artefacts can become visible in photos. For logos or UI screenshots, enable Lossless mode instead of adjusting quality.
The tool will convert GIF files, but the animation will not be preserved - only the first frame is exported. A warning is shown on the card when an animated GIF is detected. Animated WebP requires a different conversion pipeline not available in browser-based Canvas conversion.
This can happen with images that are already well-compressed (like a JPEG saved at low quality), small images, or flat graphics where PNG is the natural format. With Auto-retry enabled, the tool will automatically reduce quality and try again until the output is smaller than the original. You can also manually try a lower quality using the Re-convert panel on the card.
Yes. The interface is fully responsive and tested on mobile browsers. The comparison slider supports touch gestures. Note that AVIF conversion can be slow on older or low-powered devices since it is computationally intensive.
There is no hard limit, but very large images (above 50 MB) will show a warning since they can cause the browser tab to use significant memory. The practical limit depends on the device's available RAM. For most web images the tool handles files without any issue.
When you enable Global Resize with aspect ratio lock and enter only a width, each image calculates its own height independently based on its original dimensions. So a 1920x1080 landscape image and a 1080x1920 portrait image both get resized to width 1200, but their heights become 675 and 2133 respectively. No image is stretched or cropped.