> For the complete documentation index, see [llms.txt](https://www.ctfrecipes.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/character-encoding/utf-8.md).

# UTF-8

UTF-8 (8-bit Unicode Transformation Format) is a variable-width character encoding standard that is widely used for representing the characters of the [Unicode ](/cryptography/general-knowledge/encoding/character-encoding/unicode.md)character set. It was designed as a replacement for [ASCII ](/cryptography/general-knowledge/encoding/character-encoding/ascii.md)and other single-byte character encodings, with the goal of supporting all characters used in the world's writing systems.

## How it works ?

In UTF-8, each character is represented by one to four bytes, depending on the complexity of the character.

[ASCII ](/cryptography/general-knowledge/encoding/character-encoding/ascii.md)characters are still represented by a single byte, but other characters require more bytes to represent all of their unique details.

The advantage of UTF-8 is that **it is backwards compatible with ASCII** and can be used with existing ASCII-based systems, while also supporting a much wider range of characters.

## Resources

{% embed url="<https://www.charset.org/utf-8>" %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/character-encoding/utf-8.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.