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.
Featured ViWeb Apps
ListIPs
Create, validate, sync, and share IP/CIDR allowlists or blocklists as raw URLs for firewalls and automation.
Plahold
Generate edge-hosted placeholder image URLs with custom size, colors, text, fonts, and output format.
HeaderSec
Check website security headers and review common HTTP header protections.
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 passwords with presets, custom symbols, entropy feedback, history, notes, copy, and download.
Hash Generator
Create SHA hashes, HMAC values, and file checksums with hex/Base64 output and expected hash comparison.
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, decode, normalize, and inspect standard or URL-safe Base64 with padding and data URL controls.
Add Prefix or Suffix to Lines
Add text before or after every line, with quick Markdown bullet and HTML list presets.
Character Counter
Count characters first, then inspect words, lines, paragraphs, bytes, selected text, reading time, limits, and top words.
Text Case Converter
Convert text to uppercase, lowercase, title case, sentence case, capitalized words, inverse case, alternating case, and developer naming formats.
URL Encoder/Decoder
Encode, decode, batch-process, and parse URL components, query strings, paths, and form values.
Text Diff Checker
Compare text by words, lines, or characters with ignore options, summary counts, and unified diff copy.
Regex Tester
Test regular expressions against text, inspect matches and groups, and preview replacements.
JSON Formatter & Validator
Format, validate, sort, minify, inspect errors, and preview JSON as a tree with structure stats.
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
Generate batch URL slugs with custom separators, case, length, stop words, and replacement rules.
Random Number Generator
Generate secure random numbers with presets, uniqueness, output formats, downloads, and summary stats.
Timestamp Converter
Convert Unix seconds or milliseconds across ISO, RFC, UTC, local time, and searchable timezones.
Cron Expression Parser
Parse cron schedules, explain each field, and preview upcoming run times by timezone.
UUID v4 & v5 Generator
Generate UUID v4 and deterministic UUID v5 identifiers, format output, validate values, and track copied history.
Sortable ID 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.