How do I type the ［ fullwidth left square bracket symbol?

On Windows, type FF3B and press Alt+X. On Linux press Ctrl+Shift+U then ff3b. On any system the quickest route is the copy button on this page.

What is the code for ［?

Fullwidth Left Square Bracket is U+FF3B. In UTF-8 it takes 3 bytes. The table above lists every escape format.

Will ［ survive being pasted anywhere?

Not always. Fullwidth Left Square Bracket is a compatibility character: any system that applies Unicode NFKC normalisation — search indexes, usernames, identifiers — replaces it with [. Use it for display, not where text is normalised.

U+FF3B · Opening punctuation

Fullwidth Left Square Bracket Symbol ［

［ is fullwidth left square bracket, U+FF3B. Unicode records it as a compatibility form of [ (wide form). It was added in Unicode 1.1, and Unicode files it under Opening punctuation.

Also known as

Unicode 1.0 called this character fullwidth opening square bracket. The standard renamed it later, but documents, fonts and font-editing tools from that era still use the old name.

Codes & technical data

Unicode	`U+FF3B`
HTML hex	`［`
HTML decimal	`［`
CSS	`\FF3B`
JavaScript	`\u{FF3B}`
Python	`\U0000FF3B`
Java / C#	`\uFF3B`
Rust	`\u{ff3b}`
Swift	`\u{FF3B}`
PHP	`\u{FF3B}`
URL encoded	`%EF%BC%BB`
UTF-8 bytes	`EF BC BB`
UTF-16 bytes	`FF3B`
Base64	`77y7`
Decimal	`65339`
Decomposes to	[ (wide form)
Category	Opening punctuation (Ps)
Introduced	Unicode 1.1

Will ［ survive being pasted?

Normalisation. No. Anything that applies NFKC — search indexes, usernames, domain names, programming identifiers — rewrites ［ as [. Safe for display, not for storage.
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.

Other bracket characters

Unicode names 24 characters ending in “bracket”. They differ by direction, weight or decoration rather than by meaning.

Nearby in Halfwidth and Fullwidth Forms

Latin characters at the width of a CJK ideograph, and katakana at half width — a compatibility block for legacy East Asian encodings. Fullwidth text is often used online for a spaced-out aesthetic; it normalises straight back to ASCII.

All 53 characters in Halfwidth and Fullwidth Forms →

How to type ［

Windows	Type `FF3B` then press `Alt`+`X`
macOS	Press `Ctrl`+`Cmd`+`Space`, then search for “fullwidth left square bracket”
Linux	Press `Ctrl`+`Shift`+`U`, type `ff3b`, press `Enter`
HTML	`［`

About Unicode’s Opening punctuation category

This is an opening bracket. Editors that highlight matching pairs, and bidirectional text algorithms, both key off this category rather than off the glyph.

Frequently asked questions

How do I type the ［ fullwidth left square bracket symbol?: On Windows, type FF3B and press Alt+X. On Linux press Ctrl+Shift+U then ff3b. On any system the quickest route is the copy button on this page.
What is the code for ［?: Fullwidth Left Square Bracket is U+FF3B. In UTF-8 it takes 3 bytes. The table above lists every escape format.
Will ［ survive being pasted anywhere?: Not always. Fullwidth Left Square Bracket is a compatibility character: any system that applies Unicode NFKC normalisation — search indexes, usernames, identifiers — replaces it with [. Use it for display, not where text is normalised.