U+22A5 · Math symbol
HTML entity
⊥
LaTeX
\bot
Up Tack Symbol ⊥
⊥ is up tack, U+22A5. Unicode also records it as “base”. It was added in Unicode 1.1, and Unicode files it under Math symbol.
Also known as
- base
- bottom
Codes & technical data
| Unicode | U+22A5 | |
|---|---|---|
| HTML hex | ⊥ | |
| HTML decimal | ⊥ | |
| CSS | \22A5 | |
| JavaScript | \u{22A5} | |
| Python | \U000022A5 | |
| Java / C# | \u22A5 | |
| Rust | \u{22a5} | |
| Swift | \u{22A5} | |
| PHP | \u{22A5} | |
| URL encoded | %E2%8A%A5 | |
| UTF-8 bytes | E2 8A A5 | |
| UTF-16 bytes | 22A5 | |
| Base64 | 4oql | |
| Decimal | 8869 | |
| HTML entity | ⊥ | |
| LaTeX | \bot | |
| Category | Math symbol (Sm) | |
| Introduced | Unicode 1.1 | |
Will ⊥ survive being pasted?
- Normalisation. Yes. ⊥ is unchanged by NFKC, so it survives normalising systems intact.
- Legacy encodings. ⊥ is Unicode-only — it has no Latin-1 equivalent, so a system stuck on an 8-bit encoding cannot represent it.
- Size. 3 bytes in UTF-8. Character-limited fields — SMS, bios, some form validators — usually count bytes, not characters.
Unicode cross-references
The standard points readers of ⊥ at these characters — usually because they look alike, or because one is the correct choice where the other is often used by mistake.
Other tack characters
Unicode names 14 characters ending in “tack”. They differ by direction, weight or decoration rather than by meaning.
Nearby in Mathematical Operators
The operators mathematics and programming share — set theory, logic, calculus, comparison. Almost every character here has a LaTeX command, which is usually the fastest way to name the one you mean.
How to type ⊥
| Windows | Type 22A5 then press Alt+X |
|---|---|
| macOS | Press Ctrl+Cmd+Space, then search for “up tack” |
| Linux | Press Ctrl+Shift+U, type 22a5, press Enter |
| HTML | ⊥ |
About Unicode’s Math symbol category
Unicode classifies this as a mathematical symbol, which means software that lays out formulas treats it as an operator or relation and gives it spacing accordingly, rather than setting it tight against its neighbours like a letter.
Frequently asked questions
- How do I type the ⊥ up tack symbol?
- On Windows, type 22A5 and press Alt+X. On Linux press Ctrl+Shift+U then 22a5. On any system the quickest route is the copy button on this page.
- What is the code for ⊥?
- Up Tack is U+22A5, written in HTML as ⊥ and in LaTeX as \bot. In UTF-8 it takes 3 bytes. The table above lists every escape format.
- What kind of character is ⊥?
- Up Tack is filed under Math symbol in the Mathematical Operators block, and was introduced in Unicode 1.1. Unicode classifies this as a mathematical symbol, which means software that lays out formulas treats it as an operator or relation and gives it spacing accordingly, rather than setting it tight against its neighbours like a letter.