Format Conversion
Convert GitHub-flavored Markdown into Slack-friendly mrkdwn and flag unsupported constructs
markdown-to-slack-mrkdwnSecurity
Generate or validate 12 to 24 word BIP39 mnemonic phrases with entropy and PBKDF2-HMAC-SHA512 seed output
mnemonic-bip39-generatorText Processing
Compare resume text against a job description, normalize keyword variants, and highlight coverage gaps
resume-job-description-matcherAstronomy
Predict ISS, Hubble, and representative Starlink passes for a chosen observing point and date
iss-satellite-pass-trackerFinance
Generate a full mortgage amortization table, compare extra-payment scenarios, and visualize total interest savings
mortgage-amortization-calculatorValidation
Lint robots.txt syntax, flag risky rules, and test important URLs before you ship crawler directives
robots-txt-lint-validatorMedia
Export one image into nine social-ready crops for Instagram, X, LinkedIn, YouTube, Facebook, Xiaohongshu, and TikTok
social-media-image-resizerScience & Education
Look up electron configurations, shell distributions, valence electrons, and orbital diagrams by element symbol or atomic number
electron-configuration-calculatorMath & Numbers
Calculate molar mass, elemental composition, and mass percentages from a chemical formula
molecular-weight-calculatorMath & Numbers
Convert miles per gallon to kilometers per liter with configurable decimal precision
mpg-to-kmlMath & Numbers
Convert miles per gallon to liters per 100 kilometers with configurable decimal precision
mpg-to-l-per-100kmMath & Numbers
Convert degrees to arcminutes with configurable decimal precision
degrees-to-arcminutes