Unicode tools

The tools below run entirely in your browser. Nothing you type is sent to a server, logged, or stored. Each is a single page with one or two input fields and a live output area that updates as you type. They use only the platform: String.prototype.codePointAt, String.fromCodePoint, TextEncoder, encodeURIComponent, and String.prototype.normalize. No frameworks. No analytics. View source to see exactly how each one works.

They exist because most encoding bugs are fundamentally inspection problems. You have a string that looks fine but won't compare equal to another string, won't fit in a database column, won't round-trip through a URL, or renders as a row of question marks. The fastest way out is usually to look at the bytes — to see the actual UTF-8 sequence, the actual codepoints, the actual normalization form. These tools surface that information without making you write a script. If you need the underlying concepts explained, the guides section covers the standard from the ground up.

When to reach for which

If something is rendering wrong, start with the character inspector — it shows you what codepoints are actually in the string, which is usually enough to spot the problem (a zero-width joiner, a combining mark, a variation selector). If you need to embed a character in source code, the codepoint converter gives you every escape form. If you're debugging a database column truncation, the UTF-8 encoder shows byte counts. If equality comparison is failing, run both strings through the normalizer and look at NFC. If a URL is breaking, the URL encoder will tell you what got percent-encoded and what didn't.

Related

• What is Unicode? — a plain-English introduction
• UTF-8, UTF-16, UTF-32 compared
• Codepoint, character, glyph, grapheme
• Unicode normalization explained
• HTML entities and escapes
• All 327 Unicode blocks
• General categories