Regex Cheat Sheet

Regex Cheat Sheet | Online Free Tool | Elysia Tools

Tool usage guide

Learn when to use this tool, what it supports, and how real users apply it.

Key facts

Category: Development
Input types: select
Output type: html
Sample coverage: 4
API ready: Yes

Overview

The Regex Cheat Sheet is an interactive, searchable reference tool designed to help developers and data analysts quickly look up and test regular expression syntax, including character classes, anchors, quantifiers, lookarounds, and flags.

When to use

When you need to quickly recall specific regex syntax like lookarounds, non-capturing groups, or escape sequences.
When you want to test a regular expression against sample text in real-time without leaving your documentation.
When you need a localized regex reference guide in languages like English, Spanish, Chinese, or French.

How it works

1Select your preferred language from the options to display the localized cheat sheet.
2Use the search bar or browse categories like character classes, anchors, and quantifiers to find the syntax you need.
3Input your regular expression and test string into the built-in quick tester to verify matches instantly.

Use cases

Debugging complex validation patterns for email addresses, phone numbers, or URLs.
Learning regular expression syntax step-by-step with localized explanations and interactive testing.
Quick reference lookup during software development, data parsing, or text processing tasks.

Examples

1. Validating Email Formats

Frontend Developer

Background

A developer needs to write a client-side validation pattern for email addresses but forgets the exact syntax for non-capturing groups and character classes.

Problem

Quickly finding the correct syntax for matching specific character sets and testing the pattern.

How to use

Open the cheat sheet, search for 'character classes' and 'groups', then use the quick tester to verify the pattern against test emails.

lang: en

Outcome

The developer successfully verifies the email validation regex and understands the syntax components.

2. Extracting Log Data with Lookarounds

Data Analyst

Background

An analyst is writing a script to parse server logs and needs to match a status code only when it is preceded by a specific request method.

Problem

Recalling the exact syntax for positive lookbehinds to match the pattern.

How to use

Select the preferred language, locate the 'Lookarounds' section in the cheat sheet, copy the positive lookbehind syntax, and test it in the built-in tester.

FAQ

What regex features does this cheat sheet cover?

It covers character classes, anchors, quantifiers, groups, references, lookarounds, escape sequences, and flags.

Can I test my regular expressions directly on this page?

Yes, the tool includes a built-in quick tester to validate your regex patterns against sample text.

What languages is the cheat sheet available in?

It supports English, Chinese, Spanish, Russian, French, German, and Portuguese.

Do I need to install anything to use the tester?

No, the tester runs entirely in your web browser without any installation.

How do I search for a specific regex token?

Use the search input on the cheat sheet to instantly filter tokens by name, syntax, or description.

lang: en

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Inputs

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Learn when to use this tool, what it supports, and how real users apply it.

Key facts

Overview

When to use

How it works

Use cases

Examples

1. Validating Email Formats

2. Extracting Log Data with Lookarounds

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