Free Online Image Optimizer

Image Optimizer uses advanced compression algorithms that reduce file size while preserving visual quality. Set the quality slider (1–100) to balance file size against fidelity. For most web images, a quality setting of 70–85% delivers 40–60% size reduction with no perceptible quality loss. Converting to WebP or AVIF at the same quality typically cuts file size by an additional 25–50% compared to JPEG.

WebP is the best all-around format for web images today — it offers 25–35% smaller file sizes than JPEG and PNG at equivalent quality, and it's supported by all major browsers. For even better compression (30–50% smaller than WebP), AVIF is the next-generation choice. Image Optimizer lets you convert to both formats instantly.

Converting PNG to WebP takes three steps: (1) drag your PNG files onto the tool or click to browse, (2) select WebP as the output format in the Output Settings panel, (3) click Optimize All. Your converted files are ready to download immediately. All processing happens in your browser — no files are uploaded anywhere.

Yes. Image Optimizer is built for batch processing — drop any number of images at once and they'll all be optimized with a single click. When done, download all results together as a ZIP archive. There are no limits on the number of images or total file size.

AVIF (AV1 Image File Format) is a modern image format developed by the Alliance for Open Media. It delivers 30–50% better compression than JPEG and up to 20% better than WebP while maintaining high visual quality. All major browsers — Chrome, Firefox, Safari 16+, and Edge — support AVIF. It's an excellent choice for sites targeting modern browsers and wanting the smallest possible file sizes.

Typical reductions: JPEG recompressed at quality 80 saves 40–60% over the original; PNG converted to WebP saves 50–70%; JPEG converted to AVIF saves 50–80%. Actual results depend on image content — photos compress more than flat illustrations. Image Optimizer displays exact before/after file sizes and the percentage saved for every image.

Yes. Image Optimizer is fully responsive and runs in any modern mobile browser, including Chrome for Android and Safari for iOS 15+. All processing happens on your device using Web Workers, so performance scales with your hardware.

Your images never leave your device. Image Optimizer processes everything locally in your browser using Web Workers and the Canvas API — no files are transmitted to any server. Your images remain completely private, and the tool functions without an internet connection after the initial page load.

Yes. The Watermark panel in the sidebar lets you enter custom text (for example, your brand name or copyright notice), choose one of five positions (bottom-right, bottom-left, top-right, top-left, or center), and set the opacity from 10% to 100%. The watermark is applied at encode time using the Canvas 2D API — it is permanently burned into the output image and works with all supported output formats (JPEG, PNG, WebP, AVIF).

Yes. The Filename Pattern field in the Output Settings panel lets you define a template for output filenames. Available tokens are {name} (original filename without extension), {width} (output width in pixels), and {height} (output height in pixels). For example, {name}-optimized produces photo-optimized.webp, and {name}@{width}x{height} produces [email protected]. The pattern applies to individual image downloads and ZIP exports.

Use the Presets row at the top of the Output Settings panel. Four built-in presets are always available: Web (WebP 75%, no resize), High Quality (WebP 90%), Max Compression (AVIF 60%), and Thumbnail (WebP 75%, max 480 px). To save your own combination, dial in the settings you want and click + Save. Custom presets are stored in localStorage and persist across browser sessions.