Learn
Background on writing systems, encoding and typography.
Background on the systems underneath the tool: what Unicode is, why it exists, and how characters combine. Read this if you want to understand the foundation rather than just the surface behaviour.
None of it is required to use the site. It is here because the answers to most 'why does it do that?' questions live at this level.
These pages sit one level below everything else on the site. The guides tell you what happens; this section tells you why the system behaves that way at all. It is the difference between knowing that a character sometimes arrives as a question mark and understanding the encoding mismatch that produced it.
Nothing here is specific to this tool. Unicode, code points and combining marks are the shared foundation under every text field you will ever type into, which is why the same handful of concepts explain problems that look unrelated on the surface.
What you'll learn
- Why the same byte meant different letters before Unicode existed
- How UTF-8 keeps plain ASCII to a single byte while supporting every script
- Why a character and its on-screen appearance are separate concerns
- What problem Unicode was invented to solve, and what came before it
- The difference between a code point and an encoding such as UTF-8
- How combining characters attach marks to a base letter
- Why some Unicode alphabets have gaps in them