All Tools
DNS, email, ports, SSL, WHOIS and 30+ more tools — all in one place. Free web interface and powerful REST API.
53 tools
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.
MX Lookup
Check MX records for any domain online. Discover mail servers handling email, view priorities, IP addresses, and mail routing configuration.
SPF Checker
Check SPF record for any domain. Validate SPF syntax, verify authorized mail senders, and detect configuration issues affecting email deliverability.
DKIM Checker
Verify DKIM selector records and check domain key configuration. Validate signature setup to improve email authentication and delivery.
DMARC Checker
Check DMARC record for any domain. Validate DMARC policy mode, reporting URIs, SPF/DKIM alignment settings, and subdomain handling configuration.
Blacklist Check
Check IP or domain against 100+ DNS blacklists (RBL/DNSBL). Free email blacklist checker to detect if your mail server is blocked and causing delivery issues.
Email Validator
Verify email address deliverability with syntax check, MX record validation, and SMTP verification. Detect disposable and invalid emails.
Header Analyzer
Parse raw email headers to trace message routing, check authentication results (SPF, DKIM, DMARC), and detect delivery delays.
Email Health
Comprehensive email health score for any domain — checks MX, SPF, DKIM, DMARC, and blacklists. Get an A-F grade with recommendations.
Port Scanner
Check open ports on any IP address online. Free port scanner to scan TCP/UDP ports, detect open, closed, and filtered states across common service ports or custom ranges.
Ping Test
Ping any website or IP address online. Free ping tool to measure round-trip time, packet loss, and network latency. Test connectivity from multiple servers.
Traceroute
Trace network route to any host online. Free traceroute tool showing each hop with IP addresses, hostnames, and response times. Diagnose routing issues and latency.
IP Geolocation
Find IP address location on the map — country, city, region, ISP, ASN, timezone, and GPS coordinates. Free IP geolocation lookup for any IPv4 or IPv6 address.
Reverse IP
Find all domains hosted on a specific IP address. Discover shared hosting neighbors and verify DNS reverse lookup configuration.
Subnet Calculator
Free CIDR calculator and subnet calculator online. Compute subnet mask, wildcard mask, network/broadcast address, usable IP range, and host count from any CIDR notation.
ASN Lookup
Look up Autonomous System Number details for any IP address or ASN. View owner, country, IP ranges, and network routing information.
What Is My IP
Instantly see your public IP address with geolocation details — country, city, ISP, and ASN. No tracking, no logs.
Internet Speed Test
Test your internet connection speed — download, upload, and ping. Measure real bandwidth performance instantly.
SSL Checker
Check SSL certificate for any domain online — certificate chain, expiration date, issuer, protocol versions. Verify if SSL is valid and properly configured.
HTTP Headers
Inspect HTTP response headers for any URL. Analyze security headers (HSTS, CSP, X-Frame-Options), caching policies, and server information.
Speed Test
Measure website loading speed — TTFB, total load time, page size, compression, and resource count. Get a performance rating for any URL.
Tech Detector
Detect technologies used by any website — CMS, frameworks, JavaScript libraries, CDN, hosting, analytics, and 40+ other technologies.
Security Score
Comprehensive security audit for any domain — HTTPS, HSTS, security headers, SSL certificate, SPF, DMARC, and DNS. Get an A-F grade.
robots.txt
Fetch and parse robots.txt for any website. Analyze crawl rules, user-agent directives, sitemaps, and detect SEO configuration issues.
Image Converter & Compressor
Convert and compress images online — PNG to JPG, WebP to JPG, HEIC to JPG, AVIF, TIFF. Quality control, resize, batch processing up to 10 files. No upload to third-party servers.
Image Resizer
Resize images online to exact dimensions with aspect ratio control. Free image resizer — choose fit mode: cover, contain, fill, inside, or outside.
Image Cropper
Crop images to custom dimensions by specifying coordinates. Precise pixel-level control for cutting images to the exact size you need.
Watermark Tool
Add text or image watermarks to images with customizable position, opacity, and style. Batch processing up to 10 files with 9 placement options.
EXIF Viewer
View image metadata — camera model, resolution, GPS coordinates, date taken, ISO, shutter speed, and color channel statistics.
Image to Base64
Encode any image to Base64 data URL for embedding in CSS and HTML. Get ready-to-use code snippets for background-image and img tags.
Placeholder Generator
Generate placeholder images with custom dimensions, background color, text, and format. Perfect for mockups, wireframes, and prototypes.
Color Palette Extractor
Extract dominant colors from any image using K-means clustering. Get HEX, RGB, and HSL values with ready-to-use CSS variables.
Blur & Pixelate
Apply Gaussian blur or pixelation effect to images. Adjust intensity with a slider for privacy masking or artistic effects.
Rotate & Flip
Rotate images by 90, 180, 270 degrees or any custom angle. Flip horizontally or vertically. Combine rotation with mirroring.
Web Optimizer
Auto-optimize images for the web — resize to max 2000px, convert to WebP format, and compress with optimal quality settings.
Text Analyzer
Count characters, words, sentences, paragraphs and lines. Character breakdown by type, reading time estimate, and average word length.
Water Checker
Analyze stop word density and water content in your text. Identify filler words that add no meaning to improve writing quality.
Word Density
Analyze word frequency and density in text. View top words, 2-word and 3-word phrases with occurrence counts and percentages.
Case Converter
Convert text between 12 case formats — UPPER, lower, Title, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and more.
Text Diff
Compare two texts side by side with line-by-line diff highlighting. See added, removed, and unchanged lines with similarity score.
Lorem Ipsum Generator
Generate Lorem Ipsum placeholder text — paragraphs, sentences, or words. Configurable count with optional classic opening.
Regex Tester
Test regular expressions online with live pattern matching. Free regex tester showing all matches with index positions, lengths, and captured groups.
Base64 Encoder/Decoder
Base64 encode and decode online. Convert text to Base64 or decode Base64 strings back to plain text. View size comparison and encoding ratio.
URL Encoder/Decoder
URL encode and decode online using encodeURI and encodeURIComponent. Parse URL structure, extract query parameters, and fix encoding issues.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512 hashes online. Free hash generator for any text with hash comparison and file integrity verification.
JSON Formatter & Validator
Format, validate, and beautify JSON online. Free JSON formatter with minification, structure depth analysis, key counting, and detailed error messages for invalid JSON.
Password Generator
Generate secure passwords online with customizable length, character sets, and strength meter. Free password generator with entropy score and security rating.
UUID / ULID Generator
Generate UUID v1, v4, v7, ULID, and Nano ID. Analyze existing IDs — extract timestamps, detect versions. Custom prefixes, formats, batch generation.
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.