LOCAL / BROWSER
Network & DNSIPv4 Subnet Planner
Divide an IPv4 network into named allocations and join sibling blocks without losing sight of the address space.
The directory / 16 tools
Find the right small tool.
Sixteen small utilities for everyday network, security, data and scheduling work. Filter by the task at hand, or narrow to the thirteen that run entirely in your browser. No account, no sign-up.
16 of 16 tools / nothing to install
LIVE / API
Network & DNSDNS Explorer
Inspect public DNS records with clear distinctions between answers, missing records and resolver failures.
LIVE / API
Network & DNSEmail DNS Policy
Inspect published SPF, DMARC and a supplied DKIM selector, with the limits of DNS-only analysis made explicit.
LIVE / API
Network & DNSHTTP Inspector
Follow a bounded public redirect chain and examine status codes and response headers without loading the page.
LOCAL / BROWSER
Network & DNSEmail Header Analyzer
Unfold message headers and inspect routing and reported authentication locally, without claiming to verify the sender.
LOCAL / BROWSER
Security & identityChmod Calculator
Translate Unix permission bits, octal modes and symbolic changes, including setuid, setgid and sticky bits.
LOCAL / BROWSER
Security & identityPassword & Passphrase Generator
Generate secrets with browser cryptographic randomness and clearly stated character or word selection rules.
LOCAL / BROWSER
Development & dataJSON & YAML Workbench
Validate, format and convert structured text while protecting large numeric values from silent rounding.
LOCAL / BROWSER
Text & encodingBase64 Encoder & Decoder
Encode UTF-8 text or hexadecimal bytes and decode standard or URL-safe Base64 with explicit error reporting.
LOCAL / BROWSER
Development & dataURL Workbench
Inspect URL components and ordered query parameters or transform encoded text without visiting any address.
LOCAL / BROWSER
Security & identityJWT Decoder
Read a three-part token and its timestamp claims locally; decoded content always remains unverified.
LOCAL / BROWSER
Security & identitySHA Checksums
Calculate SHA-256, SHA-384 and SHA-512 for text or bounded local files, with progress and cancellation.
LOCAL / BROWSER
Development & dataRegex Tester
Explore JavaScript regular expressions in a terminable worker with bounded input, match counts and execution time.
LOCAL / BROWSER
Text & encodingText Diff
Compare text by line or word and export a unified difference without rendering input as HTML.
LOCAL / BROWSER
Time & schedulingCron Helper
Inspect five-field cron schedules and upcoming instants in an explicit timezone using the documented parser rules.
LOCAL / BROWSER
Time & schedulingEpoch Time Converter
Convert explicitly selected seconds or milliseconds to timestamp displays without guessing the unit or timezone.