Mailto Link Generator
Build mailto: links with multiple recipients, CC, BCC, subject and pre-filled body.
Build mailto: links with multiple recipients, CC, BCC, subject and pre-filled body.
This free Mailto Link Generator from KX Toolkit is part of our all-in-one online toolkit. It runs entirely in your browser, so your data never leaves your device for client-side operations. 100% free, forever - no paywall, no credit card, no trial.
How to use the Mailto Link Generator
- Paste your input - JSON, regex pattern, JWT, URL etc.
- Pick any flags or options the tool supports.
- Click the action button (Format, Test, Decode).
- Copy the result or download it as a file.
What you can do with the Mailto Link Generator
- Format and validate API responses while debugging.
- Test regex patterns against real input before deploying.
- Decode JWTs to inspect claims and expiry.
- Generate UUIDs for migrations, tests and seeders.
Why use KX Toolkit's Mailto Link Generator
- Browser-based: Works on Windows, macOS, Linux, iOS and Android - no install, no extension.
- Privacy-first: Client-side tools never upload your data; server-side tools delete files right after processing.
- Mobile-friendly: Full feature parity on phones and tablets - not a stripped-down view.
- Fast: Optimised for instant feedback. No artificial waiting screens, no email-gated downloads.
- One hub for everything: 300+ tools across SEO, text, image, PDF, code, color, calculators and more - skip switching between sites.
Tips for the best results
Bookmark the most-used tools - your browser bookmark bar is faster than retyping the URL every time.
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If you find this tool useful, explore the full Developer Tools collection or browse our complete tool directory. KX Toolkit is built for marketers, developers, designers, students and anyone who needs a quick utility without signing up for yet another SaaS.
How do I add multiple recipients in CC and BCC?
Separate each address with a comma. The mailto link format is mailto:to@example.com?cc=cc1@x.com,cc2@x.com&bcc=bcc1@x.com,bcc2@x.com. Some older clients accept semicolons, but commas are the spec-compliant separator and work universally. URL-encode any special characters and avoid trailing whitespace inside the address list.
Can I prefill the subject and body?
Yes. Use the subject query parameter for the subject and body for the body. Example: mailto:hi@example.com?subject=Hello&body=I%20wanted%20to%20ask. Special characters must be URL-encoded - a space becomes %20 and a newline becomes %0A. Long bodies hit URL length limits in some browsers, so keep prefilled bodies under a few thousand characters.
Why does the link not open the user's preferred email client?
The OS routes mailto links to the configured default mail handler. On desktop Chrome, you may need to authorize a web app like Gmail or Outlook to register as a handler. Mobile usually opens the native mail app. If a user has no client configured, nothing happens or a generic error shows. Provide a copyable address as a fallback.
Are mailto links a security risk?
They are low-risk but not zero. The biggest concern is exposing the address to spam crawlers; obfuscation helps but is increasingly defeated. A subtler issue is prefilling the body with sensitive information that gets quoted into the user's message. Never put tokens, account ids, or session data in the body of a mailto link.
How do I add a new line in the body?
URL-encode the newline as %0A for line feed or %0D%0A for CRLF, which some Windows clients prefer. Most modern clients accept either. Test the link in your target clients because rendering of multiple consecutive newlines varies - some collapse them to a single line break, others preserve every one.
What should I do for very long pre-filled emails?
Most browsers limit URLs to about 2,000 characters and many email clients limit mailto handlers to even less. For long content, generate a short link that opens a page with a copy-to-clipboard button, or open a compose dialog inside your web app instead of relying on the OS handler. Mailto is best for short, contextual messages.
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