hidekazu-konishi.com

Image Watermark Tool - Add Text and Logo Watermarks to Photos with Batch Processing

First Published: 2026-04-03
Last Updated: 2026-04-03

Add text or logo watermarks to your images entirely in your browser. Supports custom fonts, stroke outlines, shadow and emboss effects, 9-point positioning, tile/repeat patterns with configurable angle, and batch processing with ZIP download. Your images never leave your device — all processing happens locally using the Canvas API.

All processing is performed entirely in your browser using client-side JavaScript and the HTML5 Canvas API. No images are transmitted to any server. Your photos and images never leave your device.

• This tool is provided "AS IS" without any warranties of any kind.
• The author accepts no responsibility for any data loss or quality degradation.
• Canvas-based processing may produce slight rendering variations compared to native image editors.
• Always keep backups of your original images before processing.
• By using this tool, you accept full responsibility for any outcomes.

This tool uses client-side JavaScript for all processing. No data is transmitted to servers, no files are uploaded online, all processing happens locally in your browser. Once loaded, this tool continues to work even without an internet connection. For more details, please refer to our Web Tools Disclaimer.

🖼️

Drop images here, click to browse, or paste from clipboard

JPEG, PNG, WebP — up to 50 MB per file, 20 files max

Text Watermark Logo / Image

Quick Presets

© 2026 Your Name CONFIDENTIAL DRAFT SAMPLE DO NOT COPY

Watermark Text (press Enter for new line) © 2026 Your Name

Font Arial Verdana Georgia Times New Roman Courier New Impact Trebuchet MS Palatino

Font Size: 48px

Style

Bold Italic

Fill Color & Opacity

60%

Stroke (Outline)

2px

Stroke Opacity: 80%

Line Spacing: 1.3

Effects

Shadow Emboss

Shadow Settings

Blur: 8

Offset X: 2 Offset Y: 2

Logo Image (PNG with transparency recommended)

Click or drop logo image here

Remove

Logo Size: 150px

Opacity: 60%

Position

Tile / Repeat mode

Tile Angle: -30°

Horizontal Spacing: 200px

Vertical Spacing: 120px

Row Stagger: 60px

Rotation: 0°

Margin from Edge: 20px

Live Preview

◀ ▶

◀ Original Watermarked ▶

Drag the slider to compare original vs. watermarked

Output Format PNG (lossless, supports transparency) JPEG (smaller file size)

JPEG Quality: 92%

Images: —

Processed: —

Batch Watermarking — Apply to All Images

Watermark All Download All (ZIP) Remove All

Features

• 100% Client-Side Processing: Your images are never uploaded to any server. All watermarking happens entirely in your browser using the HTML5 Canvas API. Your photos never leave your device.
• Text Watermark with Stroke Outline: Add text watermarks with independent fill and stroke colors, each with their own opacity control. The stroke outline ensures readability on any background — a feature most online watermark tools lack.
• Logo / Image Watermark: Upload your own logo or brand image as a watermark. PNG files with transparency are fully supported for professional results.
• 9-Point Position Grid + Tile/Repeat: Place watermarks at any of 9 positions (corners, edges, center) or enable tile mode for a repeating pattern with configurable angle, spacing, and brick-pattern stagger.
• Shadow & Emboss Effects: Add drop shadows with customizable blur, offset, and color. The emboss effect creates a raised 3D appearance for a professional, subtle watermark.
• Multi-line Text & Font Control: Enter multi-line watermarks, choose from 8 web-safe fonts, adjust size, bold/italic style, and line spacing for pixel-perfect results.
• Interactive Before/After Preview: Drag the comparison slider to see the original and watermarked image side by side in real time, helping you fine-tune opacity and placement.
• Batch Processing with ZIP Download: Process up to 20 images at once with the same watermark settings. Download all watermarked images as a single ZIP file.

How to Use

1. Upload Images: Click the drop zone, drag and drop files, or paste from clipboard. Supports JPEG, PNG, and WebP up to 50 MB each (20 files max).
2. Choose Watermark Type: Select the "Text Watermark" tab for text-based watermarks or "Logo / Image" tab to use your own logo file.
3. Customize Settings: Adjust text content, font, size, colors, opacity, stroke outline, effects (shadow/emboss), position, rotation, and tile/repeat options. The live preview updates in real time.
4. Apply Watermark: Click "Apply Watermark" on individual images or "Watermark All" for batch processing. Use the before/after slider to compare results.
5. Choose Output Format: Select PNG (lossless) or JPEG (smaller file size) with quality control.
6. Download: Download individual watermarked images or use "Download All (ZIP)" for batch downloads.

Important Notes

• Font rendering may vary slightly across operating systems and browsers, as this tool uses web-safe system fonts.
• For logo watermarks, PNG files with transparent backgrounds produce the best results.
• Very large images (e.g., 4K+) with tile mode enabled may take a moment to process due to the number of watermark instances rendered.
• The watermark is permanently embedded into the output image. It cannot be removed from the downloaded file.
• Always verify the watermark placement and opacity on the preview before processing your final images.