Writing a name, a place or a loan word that needs an accent, and your keyboard does not have it?
Accent Letters adds a button to the block editor toolbar that puts the right character exactly
where the cursor is.

It covers 682 accented Latin letters used across 55 languages, generated from the Unicode
Character Database and CLDR rather than typed by hand, so the names, code points and language lists
are consistent and complete.

Finding a letter

The point of the plugin is not the grid — it is not having to hunt through one. You can search by:

the letter itself, or a plain one: e finds é è ê ë ē ĕ ė ę ě
its name: e acute, o slash, c cedilla
the accent in plain words: two dots finds every diaeresis, little hook finds the ogoneks
the language: Polish, Vietnamese, Turkish — or use the one-click language filters

What it does not do

It does not add markup to your posts. The character is inserted as text, and nothing else changes.
It does not phone home. Nothing is sent anywhere, and there is no tracking, no account and no
upsell.
It does not slow the editor down. The letter data is a separate file that is only fetched the
first time you open the picker, so the editor loads at its normal speed for everyone who never
uses it.

Formatting is preserved: insert an accent in the middle of a bold or linked word and it stays part
of that word instead of breaking the formatting in two.

Source code and build process

This plugin ships its complete, unminified source. build/index.js is generated from the files in
src/, which are included in the plugin so the compiled asset can be read, modified and rebuilt by
anyone.

src/index.js registers the block editor format type and the toolbar button.
src/picker.js is the letter picker UI.
src/insert.js is the caret insertion logic.
src/index.css is the picker stylesheet.
data/letters.json is the letter data, generated from the Unicode Character Database and CLDR.

To rebuild from source, from the plugin directory:

npm install
npm run build

That runs wp-scripts build (from the official @wordpress/scripts package), which compiles src/
into build/. No other build tooling is used, and no third-party libraries are bundled: React and
the WordPress packages are loaded as script dependencies rather than included in the file.