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resolves your domain.
Check DNS propagation across 30+ global resolvers, then audit SSL, email authentication and security headers — in one place, in seconds.
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30+
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DNS Lookups
Security & SSL
Email & SPF
Domain & Network
HTTP & Performance
All 142 tools
Every free tool on ShowDNS — no sign-up, no limits.
SSL & Security
31
- Web Security ScorecardGrade a site across transport, HSTS, content security, cookies and headers — one weighted A-F score with the fix for every gap found
- Mixed Content CheckerScan any HTTPS page for insecure HTTP resources — scripts, images, styles, and media — that trigger browser security warnings or get silently blocked.
- SSL CheckerComprehensive SSL certificate analysis including validity, expiration, chain verification, TLS versions, and security assessment
- SSL ScannerAdvanced SSL/TLS security scanner with comprehensive vulnerability assessment and configuration analysis
- SSL Expiration CheckerCheck SSL certificate expiration dates and get alerts before certificates expire
- Certificate DecoderDecode and analyze SSL certificate contents, properties, and metadata in detail
- Certificate ConverterConvert SSL certificates between PEM, DER, PKCS#7 (P7B) and PKCS#12 (PFX) formats securely in memory
- Certificate Chain CheckerVerify your SSL certificate chain order, detect missing intermediate certificates and expired certs, and download a correctly-ordered bundle. Paste a PEM bundle or check a live host
- CSR DecoderDecode Certificate Signing Request (CSR) files and view all details including subject, key type, and extensions
- CSR GeneratorGenerate Certificate Signing Request (CSR) for SSL certificates with customizable options
- Certificate GeneratorGenerate X.509 certificates for SSL/TLS, CA, and code signing purposes with full customization
- Certificate CSR MatcherVerify if SSL certificate matches its Certificate Signing Request (CSR)
- Certificate Key MatcherVerify if SSL certificate matches its private key to ensure proper key pair configuration
- Encryption Key GeneratorGenerate cryptographic keys for AES, RSA, ECDSA, and HMAC algorithms
- OCSP CheckerCheck SSL certificate revocation status using the Online Certificate Status Protocol (OCSP)
- HSTS CheckerCheck HTTP Strict Transport Security (HSTS) header configuration and preload status
- CSP CheckerValidate Content Security Policy (CSP) headers for XSS protection and content restrictions
- Cookie Security CheckerAudit every Set-Cookie header a site returns for the Secure, HttpOnly, SameSite, prefix, scope and expiry attributes
- Cross Domain Policy CheckerCheck the X-Permitted-Cross-Domain-Policies header and audit crossdomain.xml and clientaccesspolicy.xml for wildcard grants
- X-Frame Options CheckerCheck X-Frame-Options header to prevent clickjacking attacks and iframe embedding
- CORS Headers CheckerCheck and analyze Cross-Origin Resource Sharing (CORS) headers for security configuration
- TLS CheckerCheck supported TLS versions and cipher suites on a server for security compliance
- Server Signature TestDetect server software, versions, and technology stack from HTTP headers to identify information disclosure risks
- Password GeneratorGenerate secure passwords with customizable length, complexity, and character sets
- Passphrase GeneratorGenerate strong, memorable passphrases from the EFF diceware wordlist with live entropy analysis
- Htpasswd GeneratorGenerate Apache htpasswd file entries for HTTP authentication with multiple hash algorithms
- Hash Code GeneratorGenerate hash codes and checksums for data integrity verification
- SSL Tools HubComplete SSL certificate analysis, security headers validation, and HTTPS configuration testing tools
- Certificate TransparencySearch Certificate Transparency logs to find all SSL certificates ever issued for a domain — discover subdomains and check expiry status
- CSP BuilderGenerate Content Security Policy headers visually — configure directives, use presets (Strict/Moderate/WordPress), and export as HTTP header or meta tag
- Data Breach CheckerCheck if your email address has been exposed in a known data breach — see compromised data types and get actionable protection steps
DNS
21
- DNS LookupPerform DNS queries for A, AAAA, MX, TXT, CNAME, and other DNS record types
- All DNS RecordsCheck all DNS records for a domain in one comprehensive scan including all record types
- MX LookupFind mail exchange (MX) records for email server configuration and priority
- WHOIS LookupGet comprehensive domain registration information, registrar details, nameservers, and expiry dates
- TXT LookupRetrieve TXT records including SPF, DKIM, DMARC, and verification records
- CNAME LookupFind canonical name (CNAME) records for domain aliases and subdomain redirection
- SOA LookupCheck Start of Authority (SOA) records for domain authority and DNS zone information
- NS LookupFind nameserver (NS) records for domain delegation and DNS server configuration
- CAA LookupCheck Certificate Authority Authorization (CAA) records for SSL certificate issuance control
- CAA GeneratorGenerate CAA records to control which certificate authorities can issue SSL/TLS certificates for your domain
- DNSSEC ValidatorValidate DNSSEC (DNS Security Extensions) configuration, check DNSKEY, DS, and RRSIG records
- PTR LookupPerform reverse DNS lookup to find hostname from IP address (PTR records)
- DNS ServersFind and test DNS servers for a domain or IP address with performance metrics
- Nameserver Health CheckCheck your domain's own nameservers for responsiveness, DNSSEC status, and latency
- Public DNS Speed TestCompare response times across popular public DNS resolvers like Google, Cloudflare, and Quad9
- DNS Propagation CheckerWatch a DNS change roll out on a live world map — query 50 global resolvers for A, AAAA, CNAME, MX, TXT and NS records and see exactly where it has landed
- DNS Cache CheckerCheck DNS cache status and TTL values across multiple DNS servers
- Domain Expiry CheckerCheck domain expiration dates and renewal information with expiry alerts
- Domain Health CheckerFull domain audit report covering DNS, DNSSEC, WHOIS, SSL/TLS, security headers, CDN, IPv6, HTTP/2 & HTTP/3, blacklists, DNS propagation and email authentication
- Subdomain ScannerDiscover subdomains and analyze subdomain configurations and DNS records
- DNS Tools HubComprehensive DNS tools collection for record lookup, propagation checking, and domain analysis
20
- SPF LookupCheck Sender Policy Framework (SPF) records for email authentication and mail server authorization
- SPF GeneratorGenerate SPF records to authorize mail servers for your domain with visual builder
- SPF ValidatorValidate SPF record syntax and check for configuration errors and best practices
- SPF FlattenerFlatten SPF includes into IP ranges to fix permerror from more than 10 DNS lookups
- DKIM LookupFind DomainKeys Identified Mail (DKIM) records for email message signing and verification
- DKIM GeneratorGenerate DKIM keys and records for email message signing and authentication
- DMARC LookupCheck DMARC policy records for email authentication, reporting, and policy enforcement
- DMARC GeneratorGenerate DMARC policy records for email authentication with policy configuration options
- DMARC Report (RUA) AnalyzerSummarize DMARC aggregate (RUA) report XML: sending sources, SPF/DKIM alignment, volumes, and spoofing signals
- BIMI LookupCheck Brand Indicators for Message Identification (BIMI) records for email branding
- BIMI Record GeneratorGenerate a BIMI DNS TXT record with your brand logo and optional Verified Mark Certificate (VMC)
- MTA-STS & TLS-RPT GeneratorGenerate an MTA-STS policy file and the _mta-sts and TLS-RPT DNS records to enforce and monitor TLS on inbound email
- MTA-STS & TLS-RPT CheckerCheck a domain MTA-STS policy and TLS-RPT record, validating DNS records and the live HTTPS policy file
- DANE / TLSA CheckerCheck DANE TLSA records for every MX host, verify the DNSSEC chain, and match records against the live mail server certificate
- DANE / TLSA GeneratorGenerate DANE TLSA records from a PEM certificate with real SPKI hashing computed locally in the browser
- Email Health CheckerComprehensive email deliverability check including SPF, DKIM, DMARC, and MX records
- Email TroubleshooterPick the problem — going to spam, not arriving, bouncing, can’t send, late or spoofed — and get the most likely cause and the fix
- Email Header AnalyzerParse and analyze email headers, including SPF, DKIM and DMARC authentication results and routing information
- Email Spam CheckerAudit an email message before you send it — unsubscribe headers, HTML weight, hidden text, misleading links and subject-line problems
- SMTP TestTest an SMTP server end to end with a timed connection trace covering TLS, login and recipient acceptance, and optionally send a test email
Network
10
- IP LocationFind geographical location, ISP, organization, and detailed information for any IP address
- Public IPDisplay your current public IP address, location, and network information
- IP Blacklist CheckerCheck if IP address is blacklisted across multiple DNSBL and spam databases
- IPv6 Readiness TestTest whether a domain's website, nameservers and mail servers really work over IPv6, with an IPv4 comparison and fixes
- Port CheckerCheck if specific ports are open on a server or IP address with connection testing
- Online PingPing servers to check connectivity and measure response time with detailed statistics
- Subnet CalculatorCalculate IP subnet ranges, network address, broadcast, subnet mask, wildcard mask and usable hosts from any CIDR notation
- CIDR AggregatorMerge a list of IPs, ranges and CIDR blocks into the fewest CIDRs, find duplicates and overlaps, and export nginx, Apache, iptables or nftables rules
- WireGuard AllowedIPs CalculatorRoute everything through WireGuard except your LAN, an IP or any subnet: subtracts CIDR ranges and returns the exact AllowedIPs line
- Subnet Mask ConverterConvert between CIDR prefix, subnet mask and wildcard mask, or find the mask for a number of hosts, with a printable /0–/32 cheat sheet
SSH & Keys
11
- SSH Key GeneratorGenerate SSH key pairs (RSA, ECDSA, Ed25519) for secure server authentication
- SSH Key ConverterConvert SSH keys between different formats (OpenSSH, PuTTY PPK, PEM)
- PEM to PPK ConverterConvert PEM format SSH keys to PuTTY PPK format for Windows SSH clients
- PPK to PEM ConverterConvert PuTTY PPK format SSH keys to PEM format for Linux/Mac SSH clients
- SSH Key ValidatorValidate SSH key format, structure, security, and verify public/private key matching
- SSH Public Key ExtractorExtract public key from private key in various formats (PEM, PPK)
- SSH Key FingerprintCalculate and analyze SSH key fingerprints with multiple algorithms (MD5, SHA256)
- Git SSH Config GeneratorGenerate SSH configuration for Git repositories and multiple SSH keys management
- SSH Config BuilderVisual SSH configuration file builder for multiple hosts with advanced options
- SSH Tunnel HelperGenerate SSH tunnel commands for secure port forwarding and proxy setup
- SSH Tools HubSSH key management and configuration tools including key generation, conversion, and validation
Converters
5
- Base64 Encoder DecoderEncode and decode text or data to/from Base64 format with file support
- Image to Base64 ConverterConvert images to Base64 encoded strings for embedding in HTML, CSS, or data URIs
- Base64 to Image ConverterConvert Base64 encoded strings back to viewable images with preview
- Text to SpeechConvert text to speech audio with customizable voice options and languages
- Epoch ConverterConvert Unix timestamps to human-readable dates and vice versa with timezone support
Generators
17
- UUID GeneratorGenerate universally unique identifiers (UUIDs) in various formats (v1, v4)
- MAC Address GeneratorGenerate MAC addresses for network testing, virtual machines, and device configuration with multiple formats
- API Key GeneratorGenerate secure API keys with customizable formats, lengths, and character sets
- JWT Token GeneratorGenerate JSON Web Tokens (JWT) with customizable headers, payload, and signatures
- Random String GeneratorGenerate random strings with customizable length, character sets, and patterns
- JSON DatasetsGenerate sample JSON data for testing and development with customizable structures
- CSV DatasetsGenerate sample CSV data with customizable columns, rows, and data types
- XML DatasetsGenerate sample XML data structures for testing purposes with nested elements
- Excel (XLSX) DatasetsGenerate sample Excel (XLSX) workbooks with customizable columns, rows, and data types for testing
- QR Code GeneratorGenerate QR codes for URLs, text, or any data with customization options and download
- Barcode GeneratorGenerate various types of barcodes including UPC, Code 128, EAN, and more
- Crontab GeneratorGenerate cron expressions for scheduled tasks with visual interface and examples
- Robots.txt GeneratorGenerate robots.txt files to control web crawler access and search engine indexing
- Security.txt GeneratorGenerate a valid RFC 9116 security.txt file with Contact, Expires, and every optional field, plus a deployment checklist
- .htaccess GeneratorGenerate Apache .htaccess configuration files for redirects, security, and performance
- JWT DecoderDecode JWT tokens instantly — view header, payload, claims, expiry status and signature breakdown in your browser
- URL Encoder / DecoderEncode and decode URLs online — convert special characters to percent-encoding with batch mode and encodeURIComponent or encodeURI support
Web
13
- Website Redirect CheckerCheck website redirects and status codes for any URL. Detect multi-level redirects and view final destination
- HTTP Header CheckerAnalyze HTTP response headers for any website or URL with detailed header information
- HTTP/3 TestCheck if H3/QUIC is enabled on your website. Test HTTP/3 support and analyze Alt-Svc headers
- Secure Header CheckerCheck security headers like CSP, HSTS, X-Frame-Options, and more with security scoring
- Robots.txt TesterTest any URL against a site’s robots.txt — which crawlers may fetch it, which line decides it, and every syntax error that quietly disables a rule
- Security.txt TesterFetch and validate a domain security.txt file against RFC 9116 — location, syntax, required fields, expiry, and HTTPS rules
- CORS TesterTest Cross-Origin Resource Sharing (CORS) configuration and headers
- HTTP to HTTPS Redirection TestCheck whether a website properly redirects HTTP traffic to HTTPS, detect redirect loops and view the redirect chain
- WWW vs Non-WWW Redirection TestTest domain canonicalization between www and non-www, detect redirect chains and loops, and identify the preferred version
- Gzip Compression CheckerCheck if gzip compression is enabled and measure compression ratio for web performance
- HTTP Status CheckerCheck HTTP status codes and response details for any URL with detailed analysis
- Website Speed TestComprehensive website speed test with Lighthouse analysis, Core Web Vitals, performance scores, and actionable optimization recommendations
- HTTP/2 TestCheck whether a website supports HTTP/2 and review protocol negotiation details
Utilities
14
- Days Between Dates CalculatorCalculate days, weeks, months, and business days between two dates with age calculator and weekday breakdown
- Age CalculatorCalculate age in years, months, days, or any time unit with precise calculations
- DateTime CalculatorPerform date and time calculations, add/subtract time periods with timezone support
- TimerCountdown timer with customizable time and alert options
- StopwatchSimple stopwatch with lap time tracking functionality
- Regex TesterTest regular expressions online with real-time match highlighting, capture group inspection, replace mode and common presets
- JSON Formatter & ValidatorFormat, validate and minify JSON online with proper indentation and error detection
- Diff CheckerCompare two texts or code snippets side by side with highlighted added, removed and changed lines, word-level diffs and a copyable unified diff — all in your browser
- Crontab ValidatorValidate cron expressions and analyze schedule patterns with detailed explanations
- Core Web Vitals CheckerCheck Core Web Vitals (LCP, INP, CLS) and Lighthouse scores for any URL using Google PageSpeed Insights API with mobile and desktop testing
- Canonical URL TestCheck a page’s rel="canonical" tag and Link header — confirm it is self-referencing and absolute, and flag conflicting, relative or cross-domain declarations
- JavaScript Rendering TestLoad a page in headless Chrome with JavaScript off and on, and compare the text, links, title, canonical and robots tags crawlers can read before rendering
- Open Graph CheckerCheck Open Graph meta tags and preview how your page looks when shared on Facebook, Twitter, and Google — get a completeness score
- Google Analytics TestRender any page in a real browser to see which GA4, Tag Manager and legacy tags fire, the measurement hits they send, and whether consent mode is configured
Resolver Network
Trusted DNS resolvers,
queried live
We query DNS servers across 30+ regions and read each answer straight from the authoritative name servers — no local cache in the way — so you see real propagation status.
30+
Global regions
12
Record types
6
Anycast networks
Google DNS
ANYCAST · IPv4
Primary
8.8.8.8
Secondary
8.8.4.4
Cloudflare DNS
ANYCAST · IPv4
Primary
1.1.1.1
Secondary
1.0.0.1
Quad9
ANYCAST · IPv4
Primary
9.9.9.9
Secondary
149.112.112.112
OpenDNS
ANYCAST · IPv4
Primary
208.67.222.222
Secondary
208.67.220.220
CleanBrowsing
ANYCAST · IPv4
Primary
185.228.168.9
Secondary
185.228.169.9
Comodo Secure DNS
ANYCAST · IPv4
Primary
8.26.56.26
Secondary
8.20.247.20
Benchmark
Public DNS Speed Test
Benchmark your domain against every resolver above — response times, the fastest server and reliability, in one run.
6 resolvers
Response time
Fastest server
Reliability