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Underscore Symbol (_)
The underscore (_) is the low line from the Shift+hyphen key — the space substitute of usernames, file names and code, and the blank in fill-in-the-blank lines.
Underscore codes
| Code | Value |
|---|---|
| Unicode code point | U+005F |
| Unicode name | Low Line |
| HTML named entity | _ |
| HTML decimal | _ |
| HTML hex | _ |
| CSS content code | \5F |
| JavaScript / JSON | \u005F |
| Windows Alt code | No standard Alt code — copy it from the card above |
Underscore variants (7)
7 related glyphs — click any tile to copy it. Tiles with a page open that symbol's own page.
Meaning & usage
The underscore began on typewriters: typists underlined words by backspacing and striking _ under them, because the machines had no underline formatting. The name stuck even though the character's career moved elsewhere. Where systems forbid spaces, the underscore replaces them — file names like holiday_photo_2026.jpg, usernames like travel_fan_88, variables like total_count in programming.
A row of underscores makes a fill-in blank (Name: _______), and in chat a pair of them builds kaomoji faces like the shrug's arms. Its official Unicode name, Low Line, describes exactly where it sits: on the baseline, below everything else.
Examples in use
- holiday_photo_2026.jpg (no spaces allowed)
- Name: ______________ (a fill-in blank)
- ¯\_(ツ)_/¯ — the shrug's arms are underscores
How to type the underscore
Windows
Press Shift+hyphen (the key to the right of 0) — the Underscore is a standard keyboard character.
Mac
Press Shift+hyphen (the key to the right of 0) — the same as on Windows.
iPhone & Android
Most phone keyboards have no built-in key for _. Open this page on your phone, tap Copy, then paste it into your message or bio. (On Android, Gboard's emoji search finds some symbols by name.)
Linux
Press Ctrl+Shift+U, type 005f and press Enter (works in most GTK apps and terminals with IBus). Or copy it from this page.
Frequently asked questions
How do I type an underscore?
Press Shift+hyphen (the key to the right of 0) on Windows and Mac. On phones it is on the symbol keyboard.
What is the difference between _ and an underline?
The underscore is a character in the text itself — it survives copying and shows in plain text. An underline is formatting applied on top of text and can be lost when you copy.
Why do email addresses and usernames use underscores?
Spaces are not allowed in email addresses, URLs or most usernames, so _ steps in as the visible word separator.
Why does _ sometimes show as a box or question mark?
The box (called tofu) means the device or font viewing it has no drawing for U+005F (Low Line). The character itself is fine — try a different font or a newer device, or use one of the variants on this page.
Is the Underscore free to use?
Yes. _ is a standard Unicode text character published in the Unicode Character Database. You may use it in personal and commercial documents, designs and products without permission or payment.
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Data: Unicode Character Database · Page updated 2026-11-13