Free tools + honest guides for people who run everyone else's infrastructure.

Web Dev

JSON Formatter and Validator

Paste JSON, get it pretty-printed or minified. Validates syntax, highlights errors, works entirely in your browser.

Web Dev

YAML ↔ JSON Converter

Convert YAML to JSON and back in your browser. Resolves anchors and merge keys, handles multi-document files, and lets you pick the output indent.

Web Dev

Base64 Encoder/Decoder

Encode and decode Base64 in your browser, with correct UTF-8 handling, a URL-safe alphabet toggle, and file mode for binary payloads.

Web Dev

URL Encoder/Decoder

Percent-encode and decode URLs with the right rules: component, full-URI, or form encoding, plus a query string parser and builder.

Web Dev

Regex Tester

Test JavaScript regular expressions with live match highlighting, a capture group table, replace preview, and ReDoS guardrails.

Web Dev

UUID Generator

Generate v4, time-ordered v7, and Nil UUIDs in bulk, in any format, and inspect an existing UUID for its version, variant, and embedded timestamp.

Web Dev

Timestamp Converter

Convert Unix seconds, milliseconds, microseconds, and nanoseconds to ISO 8601 and human-readable dates in any IANA timezone, with a live clock.

Web Dev

Markdown ↔ HTML Preview

Side-by-side Markdown editor with GitHub-flavored Markdown support, live preview, and a sanitized HTML pane you can copy.

DevOps

Cron Expression Builder

Validate standard and Quartz cron expressions, read them in plain English, and see the next 10 fire times in any IANA timezone.

DevOps

Kubernetes YAML Linter

Paste a manifest and get severity-ranked findings: removed apiVersions, missing requests and probes, unpinned images, and permissive securityContext.

DevOps

HTTP Status Code Reference

Searchable HTTP status reference with links to the RFC and common causes for each code.

DevOps

HTTP Header Inspector

Paste a URL, see the response headers with a plain-English explanation of each.

DevOps

curl Command Builder

Visual builder for curl commands. Fill in method, headers, and body — copy the exact command.

DevOps

Nginx and Caddy Config Generator

Fill in a domain and an upstream, get a working nginx server block and an equivalent Caddyfile side by side, with TLS, headers, and rate limiting.

Security

JWT Decoder

Decode a JWT header and payload. Optionally verify HS256/RS256 signatures — all client-side.

Security

TLS Certificate Inspector

Fetch a live certificate chain by hostname or paste a PEM. Decodes subject, SANs, validity, key and signature algorithms, fingerprints and embedded SCTs.

Security

Certificate Transparency Lookup

Every certificate ever logged for a domain, with a subdomain discovery view that dedupes SANs into a copyable hostname list and a CSV export.

Security

DNS Lookup

Query A, AAAA, CNAME, MX, TXT, NS, SOA, CAA and SRV records over DoH, with TTLs, the DNSSEC AD bit, and SPF, DMARC, MX and CAA read back in plain English.

Security

Password Strength and Breach Check

Local entropy estimate plus optional HIBP k-anonymity breach check. Your password never leaves the browser.

Security

Hash Generator

CRC32, MD5, SHA-1, SHA-256, SHA-384, SHA-512 and HMAC over text or a local file. Hex or base64 output, computed in your browser.