Left Square Bracket [

[ (U+5B) is a standard Unicode character that you can copy and paste anywhere text is accepted. This page provides a concise reference with safe tips, internal links, and practical guidance so you can use it reliably across apps and platforms.

What it is and where it’s used: Left Square Bracket is part of the Symbols family (block: Basic Latin). If you need styled or decorative alternatives, try our Fancy Text tool to generate compatible text that works in most modern interfaces.

History & usage: The left square bracket marks the start of a group. It is a basic Latin character used in many systems. In writing, brackets show optional material, lists, or quoted text. In math, a left bracket begins a matrix, a set, or an interval. In programming, it marks array elements, indexing, and function parameters. It helps organize code and data and keeps syntax clear. Paired with a right square bracket, it defines boundaries and scope. The symbol appears across languages and tools, from text editors to documentation. It supports consistent formatting and readable structures. Its history is tied to the rise of organized lists and formal notation. The character is part of the Basic Latin block and sits in the common script group. It remains essential for delimiting choices, options, and grouped items in many contexts. The usage atoms note that brackets and quotes delimit groups, parameters, or quoted text in writing and code. Overall, the left square bracket is a simple yet versatile tool. It helps writers and programmers convey structure quickly and clearly.

Copy and input: the quickest method is to copy the character here. You can also insert it by its codepoint U+5B in many development tools or editors. Some operating systems provide a character viewer or input palette that lets you search by name or code and insert the glyph into documents.

Display and fallback: if you see an empty box (tofu) or a placeholder rectangle, the active font might not include this codepoint. Switching to a font with broader Unicode coverage or using a fallback font usually fixes the issue. On the web, ensure the page’s font stack includes a general‑purpose fallback.

Related references: browse the Categories for similar characters. When choosing a symbol, prefer the official codepoint for semantic clarity and better compatibility with search, copy, and accessibility tooling.

See our category page for related symbols.