Browser tool

Image Watermark Tool

Protect product photos, editorial shots, or legal documents with PolyImg’s online watermark generator—everything happens in your browser for instant, private control, great for Etsy sellers, Shopify catalogs, photographers, and “add watermark to photo online” queries.

Capabilities

Branded watermarks without leaving the browser

Batch watermarking

Drop entire folders of JPG, PNG, WEBP, or HEIC photos and PolyImg applies watermarks to all of them without leaving the browser.

Precise placement & styles

Adjust opacity, scale, tiling, padding, rotation, blend modes, and color to match your brand system.

Browser watermark tool

Everything runs locally via Canvas and WebAssembly so unreleased campaigns or sensitive documents never touch a server.

WebAssembly-powered rendering keeps brand colors accurate and outlines crisp on any background.
Workflow

Three steps to watermark batches

  1. 1Upload or drag images into PolyImg; the editor renders previews instantly in your browser.
  2. 2Configure watermark settings (logo/text, opacity, tiling, offsets) and preview across multiple assets.
  3. 3Export the watermarked images in bulk or copy them directly to your CMS or DAM.
  • Apply multiple watermark presets (logo + text, tiled + corner) in one pass and export them together.
  • Save templates to IndexedDB so teammates reuse consistent placements across campaigns.
Quality & privacy

Keep assets sharp and secure

Canvas rendering maintains high DPI output for hero banners, galleries, and social carousels, preventing blurry or noisy overlays.

Because everything runs locally, confidential shoots, legal docs, or medical imagery never leave your device—perfect for privacy-focused teams.

FAQs

Frequent questions about PolyImg’s online watermark generator. Need automation or API hooks? Reach out.