How do I visually hide or conceal matched text in Vim?

Explanation

Vim's conceal feature lets you visually hide text that matches a pattern, or replace it with a single character. This is powerful for reducing visual clutter — hiding markup syntax, long namespaces, or boilerplate while keeping the actual text intact.

How it works

• :syntax match Conceal /pattern/ conceal — hides matching text
• conceal cchar=X — replaces concealed text with character X instead of hiding it
• conceallevel controls the behavior (0=off, 1=replace with cchar, 2=hide completely, 3=hide even cchar)
• concealcursor controls concealing on the cursor line

Example

:set conceallevel=2
:syntax match Conceal /https:\/\/[^ ]\+/ conceal cchar=🔗

Before: Visit https://example.com/very/long/url for details
After:  Visit 🔗 for details (the URL is still there, just hidden)

Tips

• Set concealcursor=nvic to keep text concealed even when cursor is on the line
• Use conceallevel=1 with cchar for readable replacements
• Conceal is used by plugins like vim-markdown to hide markup syntax
• The actual text is preserved — concealing is purely visual