Alt Code & Special Character Builder
Browse, search, and build strings from special characters. Includes text transforms: upside down, fullwidth, small caps, and strikethrough.
Runs in your browser. No data leaves your device.
Frequently Asked Questions
How does the Alt Code Builder work?
The tool maintains a categorized database of Unicode characters with their Alt code numbers, names, and search tags. Text transforms (upside down, fullwidth, small caps, strikethrough) use character-mapping tables that replace each Latin letter with its Unicode equivalent from special blocks (e.g., Mathematical Sans-Serif for fullwidth, Combining Strikethrough for strikethrough). The builder concatenates selected characters into a string that you can copy via the Clipboard API.
What are Alt codes?
Keyboard shortcuts for typing special characters on Windows by holding Alt and typing a number on the numeric keypad. For example, Alt+0169 types the copyright symbol. This tool lets you find and copy characters without memorizing codes.
What text transforms are available?
Upside down text, fullwidth text, small caps, strikethrough, and other Unicode-based transforms. These work on social media, messaging apps, and anywhere Unicode text is accepted.
Do the special characters work everywhere?
Most special characters work in any application that supports Unicode, which includes modern browsers, social media, email, and documents. Some very old systems or monospace terminals may not display all characters correctly.