無料オンライン透かし追加

Yes, the 透かし追加 on Allio Tools is completely free with no sign-up or registration required. It works directly in your browser.

写真にテキストまたは画像の透かしを追加します。 No data is sent to a server — everything runs locally in your browser for maximum privacy and speed.

No installation needed. The 透かし追加 runs entirely in your web browser on any device — desktop, tablet, or mobile.

Completely safe. The 透かし追加 processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.

After the page loads for the first time, the 透かし追加 works without an internet connection for all client-side processing. Tools that fetch live external data (such as DNS or network lookups) require an active connection.

The 透かし追加 works with common image formats supported by your browser, including JPEG, PNG, WebP, and GIF. SVG support varies by tool. No format conversion plugin or driver is needed.

Yes. The 透かし追加 processes files entirely in your browser using the Canvas API. Very large files (over 20 MB) may take a few extra seconds on older or lower-powered devices. Closing other tabs can free up memory for better performance.

Yes. The 透かし追加 is built with standard browser APIs and works on all modern browsers including Chrome, Firefox, Safari, and Edge — on both desktop and mobile. No plugins, extensions, or third-party software are required.

Select and copy the result text to paste into any document or app. For image tools, a Download button saves the file directly to your device. Your browser's built-in screenshot function also captures results quickly. No account or login is required.