Regex builder online
Build and test regular expressions from sample text with clear pattern guidance. Get accurate regex, component breakdowns, and live match results in one place.
//
Test String
Scrape hundreds of webpages in one click with the Thunderbit Chrome Extension. Prefer to hand this job to AI? Use the Thunderbit API or Thunderbit MCP. Want us to run it for you? Use our Web Scraping Service.
Build Regex Patterns Faster OnlineCreate and test regular expressions with a simple interface, sample text, and pattern options. Save time while you refine matches with clear feedback.
Install fromChrome Web Store
Build Regex Patterns Faster Online
Need to match emails, phone formats, or custom text patterns? Thunderbit can help you scrape examples from websites, PDFs, docs, and images, then structure and format the data for easy use.
Extract information from subpages and paginated sites, summarize or categorize the results, and export everything to Google Sheets, Airtable, or Notion with no code required.
How to Build Regex Using Thunderbit
STEP 1Download and InstallDownload and install the Thunderbit Chrome Extension from the Thunderbit Chrome Extension Download Page. Once installed, log in or create a free account to get started.
STEP 2Open ExtensionOpen the Regex Builder Online page in your browser, then launch the Thunderbit extension. Choose the Build Regex from Sample Text tab, enter your sample text, describe the matching criteria, and select any optional flags such as global or case-insensitive.
STEP 3Click the Generate Regex ButtonClick the Generate Regex button. Thunderbit will create a regex pattern based on your sample text and matching criteria, then show a breakdown of the pattern and the matches found in the sample text. Review the result and copy the regex into your workflow or testing tool.
Learn how to build and test regex patterns
Build Regex from Sample Text
Paste sample text and describe what you want to match, such as emails, phone numbers, dates, or custom word formats. The tool then generates a regular expression based on your criteria, which helps remove the guesswork from pattern writing. It is useful for developers, analysts, and anyone who needs to work with text rules without manually assembling complex syntax.
Test Regex with Live Match Highlights
After generating a pattern, you can test it against your sample text and see which parts match in real time. This makes it easier to verify accuracy, catch edge cases, and refine the pattern before using it in code or automation. The breakdown of regex components also helps users understand why a pattern works, making it a good learning aid for beginners.
Apply Regex Flags for Better Control
You can choose common regex flags such as global, case-insensitive, multiline, dotall, and unicode to shape how the pattern behaves. This makes the output more practical for different text formats and search needs. By adjusting flags before generating the result, users can produce a pattern that is better suited for logs, forms, scraped text, or structured documents.
Understand Regex Components Clearly
The tool returns a concise explanation of the generated pattern, including the role of each part. That makes it easier to learn regex while solving real tasks, instead of treating patterns as a black box. This is especially helpful for teams that need to maintain scripts, validate data, or share patterns with others in a readable format.
Discover More Free Tools
Timestamp converter
Convert Unix timestamps to readable dates or turn dates into timestamps. Save time working with time data across formats.
HTML encoder & decoder
Encode special characters into HTML entities or decode them back to readable text for cleaner web content.
Diff checker
Compare two text blocks and spot changes, additions, or deletions in a clear view. Save time reviewing revisions and document updates.
JSON minifier
Compress JSON by removing whitespace and line breaks to reduce file size. Keep the same structure while making data easier to store and transfer.
URL parser
Parse any URL into protocol, host, path, query, and fragment so you can inspect links faster and spot issues with less manual work.
URL encoder & decoder
Encode text for safe web use or decode percent-encoded strings back to readable form. A quick way to prepare links and inspect encoded URLs.
HTML tag stripper
Remove HTML markup and keep only readable plain text for cleaner copy, simpler editing, and faster reuse.
User-agent checker
Detects and displays your browser’s user-agent string with parsed browser, OS, and device details. Useful for debugging, compatibility checks, and seeing how servers identify your device.
What users say about Thunderbit
Taryn W.Growth Strategist@Thunderbit changed how I run competitor research. I click 'AI Suggest Fields,' and it builds a clean table across paginated results—no coding, no CSS. Huge time-saver when analyzing product data from long-tail marketplaces.
Miles T.Sales Development ConsultantI use Thunderbit to grab emails and phone numbers from directories. It extracts clean contact info in one click, and exporting to Sheets or Notion takes seconds. No extra setup, no coding—just usable data ready to work with.
Rhea C.E-commerce AnalystThunderbit helps me monitor SKU data across multiple pages. I scrape the listings, then use Subpage Scraping to pull full product specs, pricing, reviews, and stock. The AI organizes everything into columns I define.
Cassian B.Real Estate AdvisorThunderbit's Scheduled Scraper makes real estate tracking easier. I describe the interval in plain English, and it automatically pulls updated listings, prices, and links without touching the setup again. Simple and very practical.
Dorian B.Content & SEO SpecialistI use Thunderbit's Field AI Prompts to clean and tag scraped blog content. It extracts titles, authors, and even suggests categories. Works great across dynamic sites and subpages—perfect for building structured SEO datasets.
Lina K.Marketplace Operations LeadWe track SKUs from niche stores using Thunderbit. Cloud Scraping handles 50 pages at a time, and for login-required sites, we switch to browser mode. It’s fast, flexible, and doesn’t need ongoing maintenance or manual edits.
Jorge F.Inbound Sales ManagerThunderbit’s AI Autofill is a lifesaver. After scraping contact info, I use it to fill lead forms directly in my browser. I just select the tab, and it fills everything using the scraped row. No manual input needed.
Alina D.Freelance ResearcherI rely on Thunderbit for extracting data from PDFs, image-based sites, and infinite scroll pages. It handles messy formats with AI and delivers ready-to-export tables I can send to Google Sheets or Airtable in seconds.
Taryn W.Growth Strategist@Thunderbit changed how I run competitor research. I click 'AI Suggest Fields,' and it builds a clean table across paginated results—no coding, no CSS. Huge time-saver when analyzing product data from long-tail marketplaces.
Miles T.Sales Development ConsultantI use Thunderbit to grab emails and phone numbers from directories. It extracts clean contact info in one click, and exporting to Sheets or Notion takes seconds. No extra setup, no coding—just usable data ready to work with.
Rhea C.E-commerce AnalystThunderbit helps me monitor SKU data across multiple pages. I scrape the listings, then use Subpage Scraping to pull full product specs, pricing, reviews, and stock. The AI organizes everything into columns I define.
Cassian B.Real Estate AdvisorThunderbit's Scheduled Scraper makes real estate tracking easier. I describe the interval in plain English, and it automatically pulls updated listings, prices, and links without touching the setup again. Simple and very practical.
Dorian B.Content & SEO SpecialistI use Thunderbit's Field AI Prompts to clean and tag scraped blog content. It extracts titles, authors, and even suggests categories. Works great across dynamic sites and subpages—perfect for building structured SEO datasets.
Lina K.Marketplace Operations LeadWe track SKUs from niche stores using Thunderbit. Cloud Scraping handles 50 pages at a time, and for login-required sites, we switch to browser mode. It’s fast, flexible, and doesn’t need ongoing maintenance or manual edits.
Jorge F.Inbound Sales ManagerThunderbit’s AI Autofill is a lifesaver. After scraping contact info, I use it to fill lead forms directly in my browser. I just select the tab, and it fills everything using the scraped row. No manual input needed.
Alina D.Freelance ResearcherI rely on Thunderbit for extracting data from PDFs, image-based sites, and infinite scroll pages. It handles messy formats with AI and delivers ready-to-export tables I can send to Google Sheets or Airtable in seconds.
