All tools
85 free diagnostics and utilities for DNS, email deliverability, websites, SSL/TLS, networks and security — no signup needed. For a one-shot health check of a whole domain, use the Super Scanner.
Utilities tools
- CSR & Key GeneratorGenerate a CSR to buy an SSL certificate
- Crontab GeneratorBuild and preview a cron schedule
- SAR Report AnalyzerVisualize CPU, memory, load, and network from sar -A
- Base64 Encoder / DecoderEncode text to Base64 or decode it back
- URL Encoder / DecoderPercent-encode or decode URL and query-string text
- HTML Entity Encoder / DecoderEscape text to HTML entities or decode them back
- Hash GeneratorMD5, SHA-1, SHA-256, SHA-384 & SHA-512 of any text
- .htpasswd GeneratorBasic-auth user:hash lines (apr1 / SHA-1)
- QR Code GeneratorEncode a link or text as an SVG/PNG QR code
- Password GeneratorGenerate a strong, random password
- UUID / GUID GeneratorGenerate one or many random v4 UUIDs
- JWT DecoderDecode a JWT's header, payload, and expiry
- JWT GeneratorBuild and HMAC-sign an HS256/384/512 token
- Regex TesterTest a regular expression with live matches and groups
- Text DiffCompare two blocks of text line by line
- Unix Timestamp ConverterConvert Unix timestamps to and from dates
- Password Breach CheckerCheck a password against known data breaches
- Nginx / Apache Config GeneratorGenerate a reverse-proxy or static-site vhost config
- Basic Linux Commands & HelpSearchable cheatsheet of common Linux commands
Network tools
DNS tools
- A RecordIPv4 address for a domain
- AAAA RecordIPv6 address for a domain
- CNAME RecordDomain alias lookup
- MX RecordMail servers for a domain
- NS RecordAuthoritative nameservers
- TXT RecordArbitrary text records
- SOA RecordZone authority details
- CAA RecordAuthorized certificate issuers
- Propagation CheckerCheck a record across global resolvers
- WHOIS LookupRegistrar, creation/expiry dates, and nameservers
- DNSSEC CheckerCheck DNSSEC signing and chain-of-trust validation
- RDNS LookupReverse DNS (PTR) lookup for an IP address
- SRV RecordService records (priority, weight, port, target)
- DS RecordDNSSEC delegation signer records at the parent zone
- Zone Transfer TestCheck whether nameservers allow an AXFR transfer
Email tools
- SPF CheckerSender Policy Framework
- DKIM CheckerSigning key validation
- DMARC CheckerMail authentication policy
- BIMI CheckerBrand indicators for email
- MTA-STS CheckerEnforced TLS mail delivery
- TLS-RPT CheckerSMTP TLS reporting
- Deliverability TestSend a test email, get a 0-10 score
- Header AnalyzerParse a received email's headers, auth results, and hop delays
- SPF Record GeneratorBuild an SPF record with a 10-lookup check
- DMARC Record GeneratorBuild a DMARC policy record from your settings
- DKIM Key GeneratorGenerate an RSA key pair and DKIM DNS record
Website tools
Security tools
Kubernetes tools
XML tools
- XML FormatterPretty-print messy XML
- XML ValidatorCheck XML well-formedness
- XML MinifierStrip whitespace and comments
- XML ↔ JSON ConverterConvert between XML and JSON
- XML → YAML ConverterConvert XML to YAML
- XML → CSV ConverterExtract tabular XML data
- XML → XSD GeneratorInfer a schema from sample XML
- XSD ValidatorValidate XML against an XSD
- XPath TesterTest XPath expressions against XML
- XML DiffCompare two XML documents
- XML Escape / UnescapeEncode/decode XML entities
- XML Sitemap GeneratorBuild a sitemap.xml
JSON tools
- JSON FormatterPretty-print messy JSON
- JSON ValidatorCheck JSON syntax
- JSON MinifierStrip whitespace from JSON
- JSON ↔ YAML ConverterConvert between JSON and YAML
- JSON ↔ CSV ConverterConvert between a JSON array and CSV
- JSON Escape / UnescapeEscape text for a JSON string, or decode it
- JSONPath TesterEvaluate a JSONPath expression against JSON
- JSON Schema ValidatorValidate JSON against a JSON Schema
- JSON DiffCompare two JSON documents by structure
- JSON → CodeGenerate TypeScript, Go, or Python types