Frequently Asked Questions

Yes, completely free. No hidden charges, no subscription, no watermarks, no file limits. All 25+ tools are free for everyone, forever. We sustain the service through non-intrusive advertising.

No account, no sign-up, no email address required. Just open any tool and start using it immediately.

There is no strict limit — you can drag and drop as many files as you want. The practical limit depends on your device's RAM, since all processing happens in the browser. Most modern devices handle dozens of images simultaneously without issue. For very large batches (100+ images), we recommend processing in groups.

Yes. All tools are fully responsive and work on Android and iOS browsers. Chrome, Safari, and Firefox on mobile are all supported. Tap the upload area or use the button to select files from your camera roll.

Your images are 100% private. All processing happens entirely within your browser using JavaScript and WebAssembly. Your files are never uploaded to our servers or any third-party server. Once you close the browser tab, the files are cleared from memory completely. We physically cannot see or access your images.

Yes. Because we don't collect or process any personal image data, JustDownSize is inherently GDPR-compliant for image processing. We do use cookies for analytics and advertising (Google AdSense). You can read our full Privacy Policy and Cookie Policy for complete details.

Nothing. Since all processing happens in your browser, your images exist only in your browser's temporary memory during processing. When you download the output or close the tab, those memory objects are released. There is no cloud storage, no CDN, no log of your files.

We support a wide range of formats including JPG, JPEG, PNG, WEBP, GIF, BMP, SVG, HEIC, HEIF, AVIF, TIFF/TIF, and RAW formats (CR2, NEF, ARW). Specific format support varies by tool — each tool page lists exactly what it accepts.

The background removal tool uses a real AI model (ONNX-based neural network) that runs entirely in your browser. The first time you use it, the AI model (~45MB) needs to be downloaded. Subsequent uses are much faster as the model is cached in your browser. Processing itself takes a few seconds per image depending on your device.

At our default quality setting of 80–90%, compression is visually lossless to the human eye for typical photos. You control the quality slider on every tool. Higher quality = larger file. For web use, 75–85% quality is usually the sweet spot. Lossless formats like PNG don't lose quality at all during our PNG compression.

HEIC (High Efficiency Image Container) is Apple's default photo format on iPhones and iPads since iOS 11. It creates smaller files than JPG at the same quality. The problem: Windows, Android, and many apps and websites don't support HEIC. You need to convert to JPG for universal compatibility.

Yes. The Resize Image tool lets you set exact pixel dimensions (width × height), scale by percentage, or maintain the aspect ratio automatically. You can also switch between pixel and percentage units.

Our smart compression loop starts at high quality (90%) and iteratively reduces the quality setting until the output file size reaches 20KB or below. If the image cannot be compressed to 20KB without extreme quality loss, it will show the smallest achievable size and let you download that result.

Yes. The Watermark Image tool supports batch processing. Upload multiple images, configure your watermark text or logo once, and it will be applied to all of them. Download individually or as a ZIP.

The Blur Face tool uses AI face detection (face-api.js) to automatically detect all visible faces in an image and blur them. Detection accuracy depends on image quality, lighting, and face orientation — frontal faces are detected most reliably. Partially obscured or very small faces may occasionally be missed.

JPG is a lossy format — great for photos, smaller file sizes, but doesn't support transparency. PNG is lossless — perfect for graphics, logos, screenshots, and images requiring transparency, but files are larger. Use JPG for photos and PNG for logos/graphics.

WebP is Google's next-generation image format. It produces files 25–35% smaller than JPG at equivalent quality, and supports transparency like PNG. All modern browsers support WebP. If your website serves many images, converting to WebP can significantly improve page load speed and your Google PageSpeed score. We strongly recommend it for web use.

AVIF (AV1 Image File Format) is the newest generation image format, offering even better compression than WebP — typically 50% smaller than JPG. Browser support has improved significantly (Chrome, Firefox, Safari all support it). It's ideal for web use if you're targeting modern browsers. For maximum compatibility, stick with WebP or JPG.