> ## Documentation Index
> Fetch the complete documentation index at: https://docs.focusme.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Regular Expressions (RegEx)

> Use pattern matching to block groups of websites or applications with a single rule.

Regular Expressions (RegEx) let you match patterns instead of exact strings. A single RegEx entry can block entire categories of sites or apps.

## Enabling RegEx

<Frame caption="The RegEx checkbox on a website entry in the Plan Wizard">
  <img src="https://mintcdn.com/focusme/mkA5R_lWl__pzlm0/images/advanced-regex-checkbox.png?fit=max&auto=format&n=mkA5R_lWl__pzlm0&q=85&s=bad6f4de79e0d2ff9159d88b7196732a" width="1036" height="800" data-path="images/advanced-regex-checkbox.png" />
</Frame>

When adding a website or application entry in the Plan Wizard:

1. Enter your pattern in the text field
2. **Check the RegEx box** on that entry
3. FocusMe will treat the entry as a regular expression instead of a literal string

<Warning>If you forget to check the RegEx box, FocusMe treats your pattern as a plain text match. The entry won't work as expected.</Warning>

<Info>FocusMe's RegEx matching is **always case-insensitive** — you don't need to add `(?i)` to your patterns.</Info>

## Essential Patterns

### Word Boundaries

Use `\b` to match whole words only:

```
\bsteam\b
```

Matches: `store.steampowered.com`
Does **not** match: `upstream.example.com` (because "steam" is part of "upstream")

### OR Matching

Use `|` (pipe) to match any of several options:

```
(reddit|tiktok|instagram)
```

Matches any URL or title containing "reddit", "tiktok", or "instagram".

### Combining Patterns

```
\b(facebook|instagram|tiktok|x\.com|reddit|threads)\b
```

This single entry blocks all major social media platforms. Note that `.` is escaped as `\.` in `x\.com` because `.` in RegEx matches any character.

## Practical Examples

### Block All Gaming Platforms

```
\b(steam|epicgames|origin|ea\.com|gog\.com|battle\.net)\b
```

### Block All News Sites

```
\b(bbc\.co\.uk/news|cnn\.com|dailymail|theguardian|nytimes)\b
```

### Block YouTube Shorts and Reels

```
(youtube\.com/shorts|instagram\.com/reels|facebook\.com/reel)
```

### Block All Subdomains of a Domain

```
(.+\.)?example\.com
```

Matches `example.com`, `www.example.com`, `mail.example.com`, etc.

## RegEx Quick Reference

| Pattern  | Meaning                                             | Example                                    |
| -------- | --------------------------------------------------- | ------------------------------------------ |
| `.`      | Any single character                                | `a.c` matches "abc", "a1c"                 |
| `*`      | Zero or more of preceding                           | `ab*c` matches "ac", "abc", "abbc"         |
| `+`      | One or more of preceding                            | `ab+c` matches "abc", "abbc" but not "ac"  |
| `?`      | Zero or one of preceding                            | `ab?c` matches "ac", "abc"                 |
| `\b`     | Word boundary                                       | `\bcat\b` matches "cat" but not "category" |
| `(a\|b)` | Either a or b                                       | `(cat\|dog)` matches "cat" or "dog"        |
| `\.`     | Literal dot                                         | `google\.com` matches "google.com"         |
| `(?i)`   | Case insensitive (built-in — not needed in FocusMe) | `hello` matches "HELLO" automatically      |
| `[a-z]`  | Character range                                     | `[0-9]+` matches one or more digits        |

## Common Mistakes

1. **Forgetting the RegEx checkbox** — your pattern is treated as plain text
2. **Unescaped dots** — `google.com` in RegEx matches `googleXcom` too. Use `google\.com`
3. **Too broad a pattern** — `game` blocks `game.com` but also `gamestop.com` and any URL with "game" in it. Use word boundaries `\b` to be precise
4. **Testing** — try your pattern on a site like [regex101.com](https://regex101.com) before adding it to FocusMe