ImgOptimizer — Free Online Image Optimizer
ImgOptimizer is a free, browser-based image optimization tool. Compress, resize, and convert images to JPEG, WebP, AVIF, or PNG format instantly — no upload required, no server processing. Your images never leave your device.
Features
- Compress JPEG, WebP, AVIF, and PNG images with adjustable quality
- Resize images by width, height, percentage, or aspect ratio
- Convert between image formats in one click
- Batch optimization — process multiple images at once
- Social media presets for Instagram, X (Twitter), LinkedIn, Facebook
- Upload optimized images directly to Amazon S3 via presigned PUT URL — no server roundtrip
- 100% private — all processing happens in your browser via WebAssembly
S3 Upload
ImgOptimizer supports direct upload to Amazon S3 via presigned PUT URLs. After optimizing an image, click the Upload to S3 button, paste a presigned URL from your AWS SDK, and the browser uploads directly to your bucket. Compatible with any S3-compatible storage (AWS S3, Cloudflare R2, MinIO, DigitalOcean Spaces).
Developer API
ImgOptimizer provides a REST API at imgoptimizer.com/api/img for programmatic image optimization. Free plan includes 500 requests per month. Sign in with Google to get your API token. The API can be combined with S3 presigned URLs to optimize and upload images in a single server-side pipeline.
How to use
Drop an image file onto the page, paste an image URL, or click to browse. Adjust quality, size, and output format using the controls. Download the optimized image or copy the URL.