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DNS, email, ports, SSL, WHOIS and 30+ more tools — all in one place. Free web interface and powerful REST API.

6 tools in DNS & Domain

DNS Lookup

Check DNS records online for any domain — A, AAAA, MX, NS, TXT, CNAME, SOA. Free DNS lookup tool with instant nslookup results, TTL values, and authoritative server data.

DNS Propagation

Check DNS propagation across 50+ global servers worldwide. Verify that DNS changes have fully propagated after updating records.

Reverse DNS

Resolve any IP address to its hostname using PTR record lookup. Verify reverse DNS configuration for email servers and network diagnostics.

WHOIS Lookup

Find domain owner and registration details — registrar, creation date, expiry, nameservers, and registrant info. Free WHOIS domain lookup via WHOIS protocol.

Domain Age

Check when a domain was first registered and calculate its exact age. Useful for SEO analysis, trust evaluation, and domain research.

NS Checker

Verify nameserver configuration and delegation for any domain. Check NS records, response times, and consistency across DNS servers.

Browse Tools by Category

DNS & Domain Tools (6)

Check DNS records, monitor propagation, perform reverse DNS lookups, query WHOIS data, and verify nameserver configurations for any domain worldwide.

Email & Deliverability Tools (8)

Validate MX records, check SPF/DKIM/DMARC policies, scan IP blacklists, analyze email headers, and run full email health diagnostics to fix deliverability issues.

Network & IP Tools (9)

Scan open ports, run ping and traceroute tests, geolocate IP addresses, look up ASN information, calculate subnets, and check your public IP — all from your browser.

Web & Security Tools (6)

Verify SSL/TLS certificates, inspect HTTP security headers, measure page load speed, detect web technologies, generate security scores, and check robots.txt configurations.

Images & Media Tools (11)

Convert between PNG, JPEG, WebP, and AVIF formats. Resize, crop, optimize, add watermarks, extract EXIF metadata, generate color palettes, and create placeholder images.

Text Tools Tools (7)

Analyze text readability and word count, check content for water words, calculate keyword density, convert letter case, compare text differences, and test regular expressions.

Utilities Tools (6)

Encode and decode Base64 and URLs, generate MD5/SHA hashes, format and validate JSON, create strong passwords, and generate UUIDs — essential developer utilities.

Free Network Diagnostic & Developer Tools Online

NetVizor provides a comprehensive suite of 53+ free online tools for network diagnostics, domain analysis, email troubleshooting, web security auditing, image processing, and developer utilities. Every tool works directly in your browser — no installation, no registration for basic use, and no ads.

DNS & Domain Tools: Our DNS lookup tool lets you query all record types (A, AAAA, MX, CNAME, TXT, NS, SOA) for any domain. Track DNS propagation across global resolvers after making changes. Perform reverse DNS lookups to find hostnames associated with IP addresses. Run WHOIS queries to discover domain ownership, registration dates, and registrar information. Check domain age and verify nameserver configurations — essential for domain research, migration planning, and troubleshooting DNS issues.

Email Diagnostics: Identify why emails bounce or land in spam. Check MX records to verify mail server configurations. Validate SPF records to prevent spoofing. Verify DKIM signatures to ensure email authenticity. Analyze DMARC policies for proper email security. Scan your domain or IP against 50+ DNS-based blacklists (Spamhaus, Barracuda, SORBS). Parse raw email headers to trace delivery paths. Our email health tool combines all checks into a single report card.

Network & Security: Scan open ports on any server to discover running services — check SSH (22), HTTP (80), HTTPS (443), SMTP (25), or custom port ranges. Measure server response time with ping. Trace routing paths with traceroute to identify network bottlenecks. Geolocate any IP address to find its country, city, ISP, and ASN. Verify SSL/TLS certificates and check expiration dates. Inspect HTTP response headers for security misconfigurations. Detect technologies powering any website.

REST API: All tools are available programmatically via our REST API. Get a free API key with 1,000 requests per month. Use it to automate SSL monitoring, DNS validation, port scanning, email health checks, and more in your scripts, CI/CD pipelines, or monitoring dashboards. Paid plans support up to 100,000 requests per month with higher rate limits and bulk endpoints.

Frequently Asked Questions

Are these tools really free?
Yes, all tools on NetVizor are free to use in the browser with no limits. For API access, the free plan gives you 1,000 requests per month. Paid plans with higher limits are available for production workloads.
Do I need to create an account?
No account is needed for browser-based use. All tools work immediately. You only need to register if you want an API key to use the tools programmatically in your scripts or applications.
How accurate are the DNS and network tools?
Our tools query authoritative DNS servers, real-time WHOIS databases, and live network endpoints. Results reflect the current state of the internet as seen from our servers. DNS propagation checks query multiple resolvers worldwide to give you a global view of your DNS changes.
Can I use these tools for security testing?
Yes, our tools are designed for legitimate security auditing. Use the port scanner to verify your firewall rules, the SSL checker to audit certificate configurations, email tools to validate anti-spoofing policies, and the security score tool to assess your website's defense posture. Always ensure you have authorization to scan targets you don't own.
What languages are supported?
NetVizor supports 7 languages: English, Russian, Ukrainian, Spanish, German, Portuguese, and French. The entire interface, tool descriptions, and documentation are translated. The API responses are always in English for consistency.