Code Formatters & ValidatorsFree Tool

Regular Expression Tester

Provided byFreeFormatterfreeformatter.com

Tests JavaScript regular expressions against sample input, highlighting matches and capture groups in real time.

Use This Tool

developer-tools freeformatter

Screenshot of Regular Expression Tester on FreeFormatter — freeformatter.comOpen the live tool →

About this tool

Tests regular expressions by allowing users to input a pattern and sample data string into separate fields. The tool immediately runs the specified regex against the provided text, displaying the results in real time. It clearly highlights all instances where the pattern finds a match within the input string, while also isolating and labeling any captured groups defined within the expression itself. Developers and technical writers use this utility to validate complex patterns before implementing them in code or scripts. By visualizing matches and capture groups against sample text, users can quickly debug expressions, refine logic, and ensure their regular expressions perform exactly as intended across various data inputs.

Keep Exploring

Similar tools

Based on shared tags

Base64 Encoder/Decoder8 options

Encodes and decodes data using the Base64 standard, allowing users to transform information into readable or binary formats. The tool supports decoding outputs back into plain text or as downloadable binary files, offering preview capabilities for immediate verification. Beyond core encoding/decoding functions, it provides related diagnostic utilities and conversions, such as hex dump views, broadening its utility for technical data inspection. Developers, security analysts, and students use this resource to manage data integrity and perform preliminary digital forensics. It is useful for checking how various file types or strings are represented in Base64 format, validating data transmission across different systems, or preparing binary data for further analysis. The comprehensive suite of tools ensures accurate handling of diverse data inputs and outputs.

8 options🛡️ Security

JSON Validator4 options

Developers and data engineers often encounter syntax errors when working with complex JSON structures. JSON Validator provides an efficient environment for verifying the integrity of code, identifying misplaced commas, missing brackets, or incorrect data types. By pasting raw code into the editor, users receive immediate feedback that pinpoints exactly where errors occur, significantly reducing debugging time during API development or configuration management. Beyond simple validation, the interface includes a tree visualization feature that transforms flat text into a structured, navigable hierarchy. This visual representation makes it easier to inspect deeply nested objects and understand the relationships between different data points. Whether refining a configuration file or troubleshooting a server response, this utility ensures that data conforms to standard specifications while providing a clear overview of its internal architecture.

4 options✨ Code Formatters & Validators

CSV TO JSON5 options

Converts CSV files to JSON format instantly with browser-based processing. Users can upload their CSV file and select the desired options for conversion, such as specifying data types or handling empty values. The tool then processes the file in the cloud and returns the converted JSON data directly in the browser. Developers, data analysts, and anyone dealing with large sets of tabular data would find this tool invaluable. It simplifies the process of converting CSV files, which are often used for data exchange, into a format more suitable for web applications and databases. Users appreciate its quick processing speed and ease of use, saving them time and effort in manual conversion processes.

5 options🔄 Data Format Converters

YAML to JSON Converter3 options

Seamlessly bridging the gap between two of the most popular data serialization formats, the YAML to JSON Converter provides a reliable way to transform configuration files and data structures. Developers and system administrators frequently use this utility when migrating settings between environments or preparing data for APIs that require strict JSON formatting. It handles the nuances of both formats, ensuring that complex hierarchies and nested objects remain intact during the translation process. The utility offers bidirectional functionality, allowing users to switch between YAML and JSON as their project requirements evolve. It includes comprehensive support for YAML-specific features such as comments and anchors, which are often lost in basic conversion scripts. By automating the transformation, the converter helps maintain data integrity and saves time when working with Kubernetes manifests, CI/CD pipelines, or web application configurations.

3 options🔄 Data Format Converters

SQL Formatter4 options

SQL Formatter is a free online tool that helps you to format and beautify your SQL queries instantly. It supports various database systems including MySQL, PostgreSQL, SQLite, and more. With this tool, you can easily convert messy SQL code into clean, readable format without the need for any sign-up or registration.

4 options✨ Code Formatters & Validators

QR Code Generator6 options

Generates QR codes for URLs, text, and contact information. Users input data through a simple interface, select desired settings like size and color, then download or share the generated QR code image. Developers, businesses, and individuals looking to enhance digital communication and accessibility would use this tool. It helps in creating quick response codes that can be easily scanned to access websites, send messages, or contact information, making it a versatile asset for various applications.

6 options💻 Developer