# invoker.tools

> Free, fast, privacy-first developer and network tools. No sign-up, no ads, nothing tracked — most tools run entirely client-side in your browser; a few do server-side DNS and TLS lookups.

invoker.tools is a terminal-themed collection of 40 single-purpose tools for developers and sysadmins: DNS and network diagnostics, email deliverability checks (SPF/DKIM/DMARC), SSL/TLS inspection, plus generators, encoders, converters and text utilities. Each tool is one focused page with examples and FAQs. Everything is free and works without an account.

## Network & DNS tools

- [IP Checker](https://invoker.tools/ip-address): See your public IP address (IPv4/IPv6) and the request headers the server sees.
- [DNS Lookup](https://invoker.tools/dns-lookup): Query A, AAAA, CNAME, MX, TXT, NS and SOA DNS records for any domain.
- [Reverse DNS](https://invoker.tools/reverse-dns-lookup): Look up the PTR record and forward-confirmed reverse DNS (FCrDNS) for an IP address.
- [Subnet Calculator](https://invoker.tools/subnet-calculator): Compute network, broadcast, mask, host range and CIDR for IPv4 subnets.
- [WHOIS / RDAP](https://invoker.tools/whois-lookup): Registration data for a domain or IP via RDAP — registrar, status, key dates and nameservers.
- [DNS Propagation](https://invoker.tools/dns-propagation-checker): Query several public resolvers and compare answers to check whether a DNS change has propagated.

## Email deliverability

- [SPF Checker](https://invoker.tools/spf-record-checker): Validate a domain's SPF record, parse mechanisms and count DNS lookups.
- [Blacklist Check (DNSBL)](https://invoker.tools/blacklist-check): Check an IPv4 address (or a domain's A record) against major DNS blacklists like Spamhaus and SpamCop.
- [DMARC Checker](https://invoker.tools/dmarc-record-checker): Look up and parse a domain's DMARC policy and reporting settings.
- [MX Lookup](https://invoker.tools/mx-record-lookup): List a domain's mail servers by priority and resolve their IPs.
- [DKIM Checker](https://invoker.tools/dkim-record-checker): Fetch and inspect a DKIM public key for a given selector and domain.
- [Email Header Analyzer](https://invoker.tools/email-header-analyzer): Parse raw email headers to trace delivery hops, delays and authentication results.

## SSL/TLS

- [SSL/TLS Checker](https://invoker.tools/ssl-certificate-checker): Inspect a host's certificate expiry, issuer, SANs, chain and trust.

## Web

- [Meta & Open Graph](https://invoker.tools/meta-tag-generator): Generate SEO, Open Graph and Twitter Card tags with a live social-share preview.
- [HTTP Header Inspector](https://invoker.tools/http-header-checker): Fetch a URL and inspect its status, response headers, redirect chain and timing (SSRF-guarded).
- [Is It Up?](https://invoker.tools/is-it-up): Check whether a website is up or down, with HTTP status and response time.

## Generators

- [Password Generator](https://invoker.tools/password-generator): Create strong, random passwords with custom length and character sets.
- [Passphrase](https://invoker.tools/passphrase-generator): Generate memorable, high-entropy word-based passphrases.
- [UUID Generator](https://invoker.tools/uuid-generator): Generate random UUID v4 identifiers.
- [ULID / UUIDv7](https://invoker.tools/ulid-uuid-generator): Generate sortable, time-based ULID and UUIDv7 identifiers.
- [QR Code](https://invoker.tools/qr-code-generator): Create QR codes from text, URLs, Wi-Fi, vCard and more.
- [Barcode](https://invoker.tools/barcode-generator): Generate common 1D barcodes (EAN, UPC, CODE128, CODE39, ITF-14).
- [Color Palette](https://invoker.tools/color-palette-generator): Build harmonious color palettes and copy hex codes.
- [Lorem Ipsum](https://invoker.tools/lorem-ipsum-generator): Generate placeholder text by paragraphs, sentences or words.
- [Favicon Generator](https://invoker.tools/favicon-generator): Produce a favicon from letters or an emoji and download PNG/SVG.
- [TOTP / 2FA](https://invoker.tools/totp-2fa-generator): Generate a 2FA secret, provisioning QR and live one-time codes.
- [Hash](https://invoker.tools/hash-generator): Compute SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text.

## Encoders & converters

- [Base64](https://invoker.tools/base64-encode-decode): Encode and decode Base64 text, UTF-8 safe.
- [JWT Decoder](https://invoker.tools/jwt-decoder): Decode and inspect a JSON Web Token's header, payload and claims.
- [JSON Formatter](https://invoker.tools/json-formatter): Format, validate and minify JSON.
- [Cron Explainer](https://invoker.tools/cron-expression-parser): Explain a cron expression and preview its next run times.
- [Number Base](https://invoker.tools/number-base-converter): Convert numbers between binary, octal, decimal, hex and any base 2-36.
- [Chmod Calculator](https://invoker.tools/chmod-calculator): Convert between symbolic (rwx) and numeric (755) Unix file permissions.
- [URL Encode / Decode](https://invoker.tools/url-encode-decode): Percent-encode or decode text, in component or full-URL mode.
- [Unix Timestamp Converter](https://invoker.tools/unix-timestamp-converter): Convert between Unix epoch (seconds/milliseconds) and human-readable UTC and local dates.
- [JSON ↔ YAML](https://invoker.tools/json-yaml-converter): Convert data between JSON and YAML in both directions.

## Text utilities

- [Regex Tester](https://invoker.tools/regex-tester): Test JavaScript regular expressions with live match highlighting and capture groups.
- [Case Converter](https://invoker.tools/case-converter): Convert text between camelCase, snake_case, kebab-case, Title Case and more.
- [Text Diff](https://invoker.tools/text-diff): Compare two blocks of text line by line and highlight added and removed lines.
- [Word Counter](https://invoker.tools/word-counter): Count words, characters, sentences, paragraphs and lines with a reading-time estimate.

## API & MCP (for agents and scripts)

The network, email and TLS tools are callable programmatically, read-only and free:

- Human docs: https://invoker.tools/api · OpenAPI 3.1 spec: `GET https://invoker.tools/api/openapi.json`
- Discovery (tools + JSON-Schema inputs): `GET https://invoker.tools/api/v1/tools`
- Call a tool: `GET https://invoker.tools/api/v1/tools/{slug}?{args}` or `POST` with a JSON body. Response: `{ "ok": true, "tool": "{slug}", "result": { ... } }`.
- Example: `GET https://invoker.tools/api/v1/tools/dns?domain=example.com&type=MX`
- MCP server (Streamable HTTP): `https://invoker.tools/api/mcp` — exposes dns, mx, spf, dmarc, dkim, rdns, ssl and ip as MCP tools.

Rate-limited per IP; no API key needed.

## About

invoker.tools is a free, privacy-first toolbox by invoker. There is no sign-up and nothing is tracked; most tools run entirely in your browser, and only DNS/TLS lookups touch a server.