The underscore _ is at Shift+hyphen on a US keyboard. Unicode names it Low Line. It joins words where a space is not allowed, which is why it turns up in variable names, database columns and filenames. It began as a typewriter mark for underlining by overtyping.
01 All shortcuts at a glance
| Platform | Shortcut | |
|---|---|---|
| Standard US keyboard | Press Shift+- directly, it's a printable key, no code needed |
|
| Windows (any app) | Win+. or Win+; emoji/symbol picker, or Character Map (Win+R → charmap) |
|
| Mac | Control+Command+Space to open Character Viewer, search "Low Line" |
|
| Word / Outlook | Type 005F, then press Alt+X |
|
| Linux (IBus) | Ctrl+Shift+U, then 005f, then Enter |
|
| HTML / CSS | _ · \005f (CSS) |
02 Step by step, per platform
A real, followable procedure for every platform, not a thin restatement of the shortcut.
Any device (US keyboard)
- Press Shift+-, it's printed on the keycap.
- On other layouts (AZERTY, QWERTZ) the key may be in a different position or need a modifier, use the picker methods below if you can't find it.
Windows
- Open Character Map: Win+R, type charmap, press Enter.
- Search or scroll for Low Line (U+005F).
- Select it, click Copy, then paste where you need it.
Mac
- Press Control+Command+Space to open the Character Viewer.
- Type "Low Line" in the search field.
- Double-click the result to insert it.
Microsoft Word
- Type 005F.
- Press Alt+X immediately after, it converts the hex code to _.
03 Characters in this set
04 Troubleshooting & confusables
| Looks like it | But it's actually | When to use |
|---|---|---|
| - (U+002D) | Hyphen-minus | Hyphens are preferred in URLs, where search engines read them as word separators. |
| ﹍ (U+FE4D) | Dashed low line, a CJK form variant | A presentation form for East Asian text. It will break an identifier or a filename. |
| Invisible under a link | Hidden by the underline | An underscore in underlined text is easy to miss. Show such paths in a monospace font. |
05 FAQ
What is the Unicode code point for the underscore?
It is U+005F, decimal 95. Unicode names it Low Line.
Should I use underscores or hyphens in a URL?
Use hyphens. Google treats a hyphen as a word separator and has long treated an underscore as a joiner, so a hyphenated URL is read as separate words and an underscored one may not be.
What is snake case?
It is the convention of joining lowercase words with underscores, as in user_first_name. Python, Ruby and SQL use it widely, where JavaScript and Java prefer camelCase.
What does a leading underscore mean in code?
By convention it marks something internal that other code should not rely on. In Python a double leading underscore also triggers name mangling inside a class, which is a real language feature rather than a convention.
Why is the underscore hard to see in a link?
The underline of the link sits at almost the same height, so the character vanishes into it. This is a common source of mistyped file paths and email addresses copied by eye.