Visual regex workbench
Build, import, explain, test and share regex visually.
Regex guide
Regex can look intimidating, but most useful patterns are built from a small set of ideas: literal text, character classes, repetition, groups and anchors.
The easiest way to learn regex is to start with simple text matching, then add character classes, quantifiers, groups and anchors one concept at a time.
Trying each pattern against real test text helps you understand not only what matches, but also why it matches.
A literal match is the simplest regex: the pattern searches for the exact characters you typed.
For example, the regex cat matches the text cat, but it will not match dog unless you add more alternatives.
Character classes allow a regex to match one character from a set, such as a digit, a letter or a custom range.
They are useful when you do not know the exact character in advance, but you know what type of character is allowed.
Quantifiers tell the regex engine how many times an element may appear.
Symbols such as *, +, ?, {3} and {1,10} are used to make patterns optional, repeated or length-limited.
Groups let you combine several tokens and apply quantifiers or alternatives to them as a unit.
They can also capture parts of the match, which is useful for extracting values like dates, usernames or domain names.
Regex can become difficult to read when several features are combined.
Testing small changes frequently helps you catch mistakes early and understand the impact of each token.
Beginners often forget anchors, use greedy quantifiers accidentally or write patterns that are too broad.
A good regex should be specific enough to reject invalid input, but not so strict that it blocks valid real-world data.
The simplest regex is just the text you want to find.
For example, cat matches the letters c, a and t in that exact order.
catA character class lets you accept one character from a set.
[0-9] matches one digit. [A-Za-z] matches one ASCII letter.
[A-Za-z]+Quantifiers control how many times something can appear.
\d+ means one or more digits. \d{4} means exactly four digits.
\d{4}-\d{2}-\d{2}The safest way to build a regex is to test it step by step against positive and negative examples.
That is exactly what the visual builder is designed for.