Paste emails, logs, HTML, or any text containing domains. Instantly extract and validate against 9,727+ TLDs from IANA. Export to CSV, JSON, Excel, and more.
Professional Domain Extraction & Validation Tool
4.7(156 reviews)
9,727+
TLDs Validated
100%
Client-Side
25,000+
Active Users
Free
Forever
Complete Guide to Domain Extraction
Domain extraction is the process of automatically identifying and isolating domain names from unstructured text, logs, emails, HTML, or any text-based content. Whether you're a security analyst parsing firewall logs, a developer auditing API references, or a marketer cleaning email lists, domain extraction transforms messy data into clean, actionable insights.
Why Extract Domains from Text?
In today's digital landscape, domains are everywhere - buried in server logs, scattered through email databases, hidden in scraped web content, and referenced throughout source code. Manual identification is tedious, error-prone, and doesn't scale. Automated domain extraction solves these challenges.
Security & Threat Intelligence: Cybersecurity teams extract domains from logs, malware samples, phishing emails, and network traffic to identify threats, build blocklists, and track malicious infrastructure.
Email Marketing & CRM: Marketing teams extract and validate domains from subscriber lists, removing invalid addresses, identifying corporate email domains, and segmenting audiences by domain.
Log Analysis & Monitoring: DevOps engineers parse server logs, application logs, and DNS query logs to audit external API calls, identify third-party dependencies, and monitor domain access patterns.
Data Cleaning & Validation: Data analysts extract domains from messy datasets, CSVs, scraped content, or legacy databases to standardize, deduplicate, and validate domain information.
Competitive Intelligence: SEO professionals and market researchers extract competitor domains from industry publications, backlink data, and web scrapes to analyze market positioning.
Compliance & Auditing: IT auditors extract domains from configuration files, documentation, and code repositories to verify third-party integrations and assess data privacy compliance.
How Domain Extraction Works
Our domain extractor uses sophisticated pattern matching combined with TLD validation to accurately identify domains while filtering noise:
Text Scanning: The algorithm scans your input text character-by-character, looking for patterns that match domain name syntax (alphanumeric labels separated by dots).
Pattern Recognition: Uses regex patterns optimized for domain syntax - matching labels, handling hyphens correctly, and identifying TLD endings. Handles subdomains, country-code TLDs, and new gTLDs automatically.
TLD Validation: Each extracted candidate is validated against our database of 9,727+ official TLDs from IANA. Invalid or non-existent TLDs are flagged, helping identify typos, internal domains, or data quality issues.
Deduplication: Removes duplicate entries using case-insensitive matching. "Example.COM" and "example.com" are treated as identical.
Sorting & Categorization: Results are sorted with valid domains first, then alphabetically. Statistics are calculated including TLD distribution, length analysis, and duplicate frequency.
Common Use Cases & Examples
Cybersecurity - Firewall Log Analysis
Security teams paste firewall or proxy logs containing thousands of lines. The tool extracts all accessed domains, validates TLDs, identifies suspicious invalid TLDs (often used in malware), and shows frequency analysis to spot command-and-control domains appearing repeatedly. Export to CSV for SIEM ingestion.
Email Marketing - List Cleaning
Marketing managers paste email lists with 10,000+ addresses. Extract all domains to identify corporate email domains (for B2B segmentation), remove invalid TLD addresses (bounces), find duplicate domains, and export cleaned lists for CRM import. Saves hours of manual spreadsheet work.
Development - API Dependency Audit
Developers paste source code or configuration files to extract all referenced domains (APIs, CDNs, third-party services). Identifies external dependencies, audits for security compliance, and documents integration points. Essential for security reviews and migration planning.
What Our Users Say
Alex Morgan
Security Analyst at Enterprise Cybersecurity Firm
"We use this daily to extract domains from server logs and email dumps for threat analysis. The TLD validation feature helps us instantly identify suspicious domains with invalid or uncommon extensions. Saves hours of manual work."
18 September 2025
Jessica Taylor
Email Marketing Manager at E-commerce Platform
"Perfect for cleaning up our email subscriber lists. I paste lists with thousands of entries, extract all domains, and quickly identify invalid addresses. The export to CSV feature is exactly what I needed for our CRM integration."
25 August 2025
Raj Patel
DevOps Engineer at SaaS Startup
"Incredibly useful for parsing deployment logs and configuration files. The ability to extract domains from any text format means I can quickly audit our infrastructure references. Wish it had an API for automation."
5 September 2025
Sophie Chen
Content Moderator at Social Media Company
"We moderate millions of user posts daily. This tool helps extract domains from flagged content for blocklist management. The duplicate detection shows us which domains appear most frequently in spam reports."
30 August 2025
Daniel Brown
Data Analyst at Marketing Research Agency
"Analyzing competitor mentions across the web requires extracting domains from scraped data. This tool handles messy HTML and text perfectly. The TLD analysis shows us which extensions our competitors are using for different markets."
12 September 2025
Priya Sharma
Domain Investor at Independent Investor
"I extract domains from expired domain lists, auction catalogs, and drop lists. Being able to paste thousands of lines and get clean, validated output in seconds is fantastic. The invalid TLD filtering helps me avoid wasting time on fake listings."
15 August 2025
Frequently Asked Questions
How does the domain extraction algorithm work?
Our domain extractor uses advanced regular expression patterns to identify domain names in any text format:
Pattern Matching: The algorithm scans for text patterns matching valid domain syntax (labels separated by dots, ending with a recognized TLD).
TLD Validation: Each extracted domain is validated against our database of 9,727+ official TLDs from IANA, including .com, .org, country codes (.uk, .de), and new gTLDs (.tech, .store).
From URLs: Extracts domains from full URLs like https://www.example.com/path
From emails: Extracts domains from email addresses like user@example.com
Invalid domains (flagged): example.local, server.invalid, test.internal - detected but marked as invalid TLDs
Can I extract domains from email lists or server logs?
Yes! This is one of the primary use cases. Simply paste your email list, server access logs, application logs, or any text-based file. The tool will automatically scan the entire content, identify all domain patterns, and extract them. It handles mixed formats perfectly - whether you have CSV lists, Apache/Nginx logs, JSON API responses, or plain text. Email addresses like 'user@example.com' will extract 'example.com', URLs like 'https://website.co.uk/path' will extract 'website.co.uk'. This makes it perfect for log analysis, email list cleaning, security auditing, and data extraction workflows.
What happens to invalid or fake TLDs?
The tool identifies and flags domains with invalid TLDs (extensions not recognized by IANA/ICANN):
Detection: All extracted domains are checked against our database of 9,727+ valid TLDs. Flagging: Invalid TLDs are marked with a red "Invalid TLD" badge in results. Separation: Statistics show counts of valid vs. invalid domains. Export control: Export functions typically include only valid domains by default.
Common invalid TLDs: • Internal network: .local, .lan, .internal, .corp • Development: .dev (if not the official Google .dev), .test, .localhost • Typos or fake: .comm, .nett, .orgg • Expired/withdrawn: Rarely, TLDs that have been removed from the root zone
This helps identify data quality issues, test/development entries, and potential typos in your source data.
How many domains can I extract at once?
There's no hard limit on the number of domains you can extract. The tool handles large text inputs efficiently - users regularly extract thousands of domains from log files, email databases, and scraped web content. Browser performance may vary with extremely large inputs (10,000+ domains), but the extraction algorithm itself is optimized for speed. For best performance with very large datasets (100,000+ domains), consider breaking your data into chunks of 50,000 lines. The tool processes text client-side in your browser, so there are no server restrictions or rate limits.
What export formats are supported?
Export extracted domains in multiple professional formats:
CSV (Comma-Separated Values): Perfect for Excel, Google Sheets, database imports. Includes domain and TLD columns.
JSON: Structured data format for programmatic use, API integration, or database insertion. Includes domain, TLD, and validity status.
TXT (Plain Text): Simple newline-separated list of domains, one per line. Great for blocklists, allow lists, or further processing.
XML: Structured XML format for enterprise systems, SOAP APIs, or legacy applications.
All exports include only valid domains by default (those with recognized TLDs). The export happens instantly in your browser with no server upload required, ensuring your data privacy.
Can I use this for email validation or spam detection?
Yes! The domain extractor is excellent for email validation workflows and spam analysis. Use cases include: (1) Extract domains from email address lists to validate sender domains against known TLDs, (2) Identify suspicious domains with invalid or uncommon TLDs often used in spam/phishing, (3) Analyze domain frequency - spam often reuses the same domains repeatedly (see Duplicates tab), (4) Bulk email list cleaning - paste thousands of addresses and get valid domains instantly, (5) Blocklist creation - extract domains from spam reports and export to your email filter. However, note that TLD validation alone doesn't confirm email deliverability - a valid TLD doesn't mean the domain has active MX records or accepts email. For complete email validation, combine this tool with DNS/MX record checks.
How does duplicate detection work?
The Duplicates tab automatically identifies domains that appear multiple times in your input text:
Case-insensitive matching: Example.com, example.com, and EXAMPLE.COM are treated as the same domain. Count tracking: Shows exactly how many times each duplicate appears. Sorted by frequency: Most frequently appearing domains listed first.
Use cases: • Spam detection: Spammers often reuse domains heavily • Data quality: Identify accidental duplicates in your lists • Popular domain analysis: See which domains appear most in logs or datasets • Deduplication: Clean lists before importing to CRM or email systems
The main extraction already deduplicates results, so the Duplicates tab shows you what was removed and how often each domain appeared.
What analysis features are included?
The Analysis tab provides detailed statistics about extracted domains:
Domain Length Statistics: • Average domain length in characters • Shortest domain found • Longest domain found Useful for identifying suspiciously short/long domains often associated with spam or phishing
TLD Distribution: • Top 10 most common TLDs in your data • Count for each TLD Shows you the market/geographic breakdown of domains in your dataset
Validation Summary: • Total domains found • Valid domain count (recognized TLDs) • Invalid domain count (unrecognized TLDs) • Unique vs. duplicate counts
This analysis is invaluable for security auditing, market research, and data quality assessment.
Is my data safe? Do you store extracted domains?
Your data is completely private and secure. The domain extraction happens entirely in your browser using client-side JavaScript - no data is ever sent to our servers. When you paste text or extract domains, everything is processed locally on your device. We cannot see, store, or access any of the text you paste or domains you extract. Export functions also work client-side, generating files directly in your browser. This makes the tool safe for extracting domains from confidential logs, customer data, internal documentation, or sensitive security information. Clear your browser cache to remove any local history if needed.
Can I extract domains from HTML or code?
Absolutely! The tool is format-agnostic and works perfectly with HTML, source code, and markup. It will scan through HTML tags, attributes, JavaScript code, CSS files, XML, JSON, and any other text-based format to find domain patterns. Common uses: (1) Extract domains from scraped web pages or HTML emails, (2) Find API endpoints in source code, (3) Identify external resources in web pages (scripts, images, iframes), (4) Audit third-party domains in your codebase, (5) Parse configuration files for domain references. The regex pattern focuses on valid domain syntax, so it automatically filters out HTML tags, code syntax, and other noise - extracting only the actual domain names.
What's the difference between subdomains and root domains?
The tool extracts the full domain as written in your text:
Root/Apex Domain: The base domain registered with a registrar • Examples: example.com, google.org, amazon.co.uk • These are what you actually purchase from domain registrars
Subdomain: A prefix added before the root domain • Examples: www.example.com, mail.google.com, api.service.io • These are configured by the domain owner, not registered separately
In extraction results: The tool preserves the full domain as it appears in your text. So "mail.google.com" is extracted as "mail.google.com", not shortened to "google.com". This is important for log analysis and security work where the specific subdomain matters (e.g., distinguishing between legitimate mail.example.com and phishing mail-example.com).
How accurate is the TLD validation?
TLD validation is extremely accurate - we validate against the official IANA Root Zone Database with 9,727+ recognized TLDs, updated regularly. Our database includes: (1) All country-code TLDs (ccTLDs) like .uk, .de, .jp, .au, (2) Generic TLDs (gTLDs) like .com, .org, .net, (3) New gTLDs from ICANN's expansion (.tech, .store, .app, .io), (4) Sponsored TLDs (.gov, .edu, .mil), (5) Infrastructure TLD (.arpa), (6) Second-level domains (.co.uk, .com.au, .org.nz). The validation checks if the rightmost label (TLD) exists in the official registry. False positives are rare and usually indicate the TLD was very recently added (we update weekly). False negatives are extremely rare - if a domain is publicly accessible on the internet, its TLD will be validated correctly.
Can this help with cybersecurity and threat analysis?
Yes! Security teams use domain extraction for multiple threat intelligence workflows:
Security Use Cases: • Log analysis: Extract domains from firewall logs, proxy logs, DNS query logs to identify suspicious patterns • Email security: Parse phishing emails to extract malicious domains for blocklisting • Incident response: Quickly extract all domains from malware samples, memory dumps, or network captures • Threat intelligence: Process feeds of IOCs (Indicators of Compromise) to extract domain indicators • Invalid TLD detection: Suspicious domains often use invalid TLDs (.local, .internal) or typo TLDs (.comm instead of .com) • Frequency analysis: Command-and-control domains often appear repeatedly in logs - use duplicate detection • TLD patterns: Certain TLDs (.tk, .ml, .ga free domains) are statistically more common in phishing
Export findings in JSON/CSV for SIEM integration or security orchestration platforms.
What regex pattern does the extractor use?
For technical users, the core extraction pattern is:
Pattern breakdown: • \b - Word boundary to avoid partial matches • ([a-z0-9]([a-z0-9-]*[a-z0-9])?\.)+ - Matches domain labels (alphanumeric, hyphens allowed in middle, separated by dots) • [a-z]{2,} - Matches TLD (2+ letters) • gi - Global, case-insensitive matching
What it matches: example.com, subdomain.example.co.uk, api-v2.service.io What it doesn't match: Invalid syntax like -invalid.com, domain-.com, .com (no domain), IP addresses
The pattern is optimized to balance precision (avoiding false matches) with recall (catching all valid domains).
Can I use this tool programmatically or via API?
Currently, the tool is a web-based interface only, with no public API available. However, because all processing happens client-side using JavaScript, developers can: (1) Use browser automation (Puppeteer, Selenium) to programmatically paste text and extract results, (2) Inspect the source code (available in our open-source repository) and integrate the extraction logic into your own applications, (3) Use the export functions to download results in JSON/CSV for pipeline integration. For high-volume or automated extraction needs, we recommend implementing the regex pattern in your preferred language (Python, JavaScript, Go, etc.) and validating against the public suffix list or IANA TLD database.
Why Choose Our Domain Extractor?
100% Private & Secure
All processing happens in your browser. Your data never touches our servers. Perfect for confidential logs, customer data, or sensitive security analysis. No storage, no tracking, complete privacy.
Lightning-Fast Extraction
Optimized regex engine processes thousands of domains per second. Extract domains from massive log files, email databases, or scraped content instantly. No loading, no waiting - results appear immediately.
Comprehensive TLD Validation
Validates against 9,727+ official TLDs from IANA including country codes, new gTLDs, and second-level domains. Instantly identifies invalid, typo, or internal TLDs that shouldn't appear in production data.
Advanced Analysis & Statistics
Automatic TLD distribution analysis, duplicate detection with frequency counts, domain length statistics, and valid/invalid categorization. Turns raw extraction into actionable intelligence.
Professional Export Formats
Export to CSV (Excel/Sheets), JSON (API integration), TXT (blocklists), XML (enterprise systems). One-click downloads optimized for your workflow - database imports, SIEM ingestion, or CRM uploads.
Intelligent Deduplication
Case-insensitive duplicate removal with detailed frequency analysis. See which domains appear most often - critical for spam detection, log analysis, and data quality assessment.
Format-Agnostic Processing
Works with any text format: HTML, JSON, XML, CSV, logs, emails, source code, plain text. No preparation needed - paste messy data and get clean domain lists. Perfect for developers and analysts.
No Limits, Always Free
Extract unlimited domains, no registration required, no rate limits, no paywalls. Process gigabytes of logs, million-line CSV files, or entire email databases without restrictions.
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