Web tools
Free online web tools for Developers.
Tools.viweb.net provides fast browser-based utilities for JSON formatting, DNS lookup, SSL and redirect checks, encoding, timestamps, password generation, QR codes, email security, cloud reference data, and everyday website troubleshooting. The previous static version is preserved at /v1/ for compatibility.
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Networking Tools
Display IPv4 & IPv6
See your current public IPv4 and IPv6 addresses with connection details.
DNS Lookup
Query DNS records for a domain and inspect the returned values.
CIDR / Subnet Calculator
Calculate IPv4 CIDR network ranges, usable hosts, masks, wildcards, and subnet splits.
Redirect Checker
Follow URL redirects and review each HTTP status in the chain.
HTTP Headers Checker
Inspect HTTP response headers and evaluate common browser security header protections.
SMTP Tester
Test SMTP connection settings and diagnose mail server responses.
IP Checker
Look up location, ASN, and network details for an IP address.
Whois Lookup
Look up domain registration and nameserver information.
Security Tools
SSL/TLS Checker
Check certificate validity, issuer, dates, and TLS configuration for a host.
Password Generator
Generate strong random passwords with configurable length and character sets.
Hash Generator
Create common hashes from text for checksums and verification.
JWT Decoder & Verifier
Decode JWT headers and payloads, inspect claims, and verify supported signatures locally.
Self-hosted SSL Generator
Create self-signed certificates for local and self-hosted testing.
CSR Generator
Generate certificate signing requests and private keys for SSL issuance.
Email Security Checker
Check SPF, DKIM, and DMARC records for email authentication health.
SSH Key Generator
Generate SSH key pairs for secure server authentication.
Text and Data Tools
Base64 Encoder/Decoder
Encode plain text to Base64 or decode Base64 back to readable text.
Add Prefix or Suffix to Lines
Add text before or after every line, with quick Markdown bullet and HTML list presets.
URL Encoder/Decoder
Escape or unescape URL text for query strings, paths, and forms.
Text Diff Checker
Compare two text blocks and highlight what changed.
Regex Tester
Test regular expressions against text, inspect matches and groups, and preview replacements.
JSON Formatter & Validator
Format, validate, and inspect JSON with readable indentation.
YAML, TOML & XML Formatter
Format and validate YAML, TOML, and XML, with parsed JSON previews for structured data.
CSV to JSON Converter
Convert CSV to JSON or JSON arrays back to CSV with headers, delimiters, and proper quoted fields.
Utility Tools
Slug Generator
Turn titles or phrases into clean URL-friendly slugs.
Random Number Generator
Generate random numbers across a chosen range and quantity.
Timestamp Converter
Convert Unix timestamps and human-readable dates across formats.
Cron Expression Parser
Parse cron schedules, explain each field, and preview upcoming run times by timezone.
UUID Generator
Generate UUIDs for identifiers, fixtures, and development workflows.
UUID v7, ULID & NanoID Generator
Generate sortable UUID v7 values, ULIDs, and compact NanoID-style identifiers locally.
Sitemap URL Extractor
Extract URLs from XML sitemaps for audits, crawls, and exports.
Robots.txt Tester
Parse robots.txt directives, list sitemaps, and test crawler access for URLs and user agents.
Open Graph Preview
Inspect title, description, canonical, favicon, Open Graph, and Twitter card metadata.