How Mark My Pics works
Watermarking a single photo or a full batch takes about a minute from start to finish. Here is exactly what happens at each step, and what is going on behind the scenes.
1. Upload your images
Drag and drop up to 10 photos at once, or click the upload zone to browse files. We accept JPG, JPEG, PNG, WEBP, HEIC, and HEIF — including the high-efficiency HEIC format that iPhones use by default. Files stay on your device the whole time; nothing is uploaded to our servers.
2. Choose text or a logo
Type a copyright line, your brand name, a website URL, or any short label — up to 60 characters. Pick a font from our curated list, set a color with the picker or hex code, and adjust opacity. Prefer a logo? Upload a transparent PNG and Mark My Pics will scale it cleanly across every photo in your batch.
3. Position and style
Snap your watermark to any of nine grid positions — corners, edges, or center — or fine-tune the X/Y offset for precise placement. Rotate to any angle, scale up or down, and use the live preview to confirm the look before you export. Settings carry across every image in your batch automatically.
4. Download
Export a single image as JPG, PNG, or WEBP at the quality level you choose. Batch processing? Download everything as a single ZIP with one click. Your watermarked files go straight to your browser's Downloads folder — no email, no sign-up, no waiting room.
What's happening behind the scenes
Mark My Pics uses your browser's HTML5 Canvas API to render the watermark on top of your image at full resolution. Everything — decoding the file, drawing the overlay, re-encoding to your chosen format — happens locally in JavaScript. Because there is no server round-trip, processing is limited only by your device's memory and CPU. Modern phones and laptops handle batches of 4K photos comfortably.
For HEIC files, we use a WebAssembly decoder so iPhone photos work even on browsers that don't natively support the format. Output files use the standard JPEG, PNG, or WEBP encoders built into your browser, so the result is perfectly compatible with every social platform, marketplace, and editing tool.