BOFH — Browser-Native Dev Toolkit

One HTML file. Twenty tools. Zero data leaving your device.

Named after the Bastard Operator From Hell — because your tokens, keys, and logs deserve better than some random website's S3 bucket.

Stop pasting your secrets into the internet.

Open in browser → bofh.naklitechie.com

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Why

Every developer keeps 20+ browser tabs open for the same mundane transformations: jwt.io, regex101, jsonformatter.org, base64encode.org, epochconverter.com…

Every one of those sites receives your input. JWTs with production auth tokens. JSON responses with PII. Regex patterns mining your logs.

BOFH does it all locally. Single HTML file. Open it from anywhere — GitHub Pages, python3 -m http.server, a file:// URL, any static host. No build step, no npm, no framework. No telemetry, no fonts loaded from a CDN, no third-party scripts.

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What's in it — 20 modules across 4 categories

Text & Data

Module	What it does
JSON	Format, validate, minify, collapsible tree view, JSONPath query
YAML	YAML ↔ JSON conversion via js-yaml (lazy CDN)
Markdown	Live preview with GFM tables / fenced code via marked.js (lazy CDN)
Diff	Line-level diff with inline word-level highlighting (LCS, pure JS)
CSV	Drop CSV/TSV → sortable table, filter, regex find/replace, dedup, export. Papa Parse (lazy CDN).
SQL	Drop CSV → BOFH infers types and creates a SQLite table → write SQL → results. sql.js WASM (~1MB, lazy).
Log Viewer	Drop a log file → virtual scroll up to 500K lines + live regex search. Pure JS.

Crypto & Security

Module	What it does
JWT	Decode header/payload, verify HS256/384/512 and RS256/384/512, expiry & nbf checks, claim highlights
Hash	SHA-1/256/384/512 + MD5 + HMAC. Text or file. Hex / base64 / base64url. Compare against expected.
Base64	Encode/decode text and files, URL-safe variant
URL	Encode/decode (component or whole-URL), parse into components + query params, build from base + kv pairs
Keys	Generate RSA (2048/3072/4096) or ECDSA (P-256/384/521) keypairs → SPKI/PKCS#8 PEM. Decode PEM public keys and X.509 certificates.

Converters & Generators

Module	What it does
Timestamp	Unix epoch ↔ human, timezone-aware (Intl), relative time
UUID	Generate v4 (random) and v7 (time-ordered, database-friendly), bulk, parse & validate
Regex	JavaScript regex with live highlighting, capture groups, all six flags, preset library, live replace preview
Color	Convert hex / rgb / hsl / oklch / named via the browser's CSS parser. WCAG contrast ratio with AA / AAA pass-fail badges.
IP / Subnet	IPv4 CIDR calculator: network, broadcast, mask, wildcard, hosts, address class, RFC1918 type, 32-bit binary view.
Cron	Parse 5-field cron, plain-English description, expanded value sets, next 10 run times in your local timezone.

Reference

Module	What it does
HTTP Status	Searchable reference for every HTTP status code (1xx–5xx, including WebDAV).
User Agent	Your current navigator.userAgent parsed into browser/version/engine/OS/device, plus Client Hints when available. Paste any UA to parse.

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How

• One HTML file — markup, CSS, and ~1300 lines of JS, all inline
• Vanilla JS, no framework — each module is a self-contained object with an init(container) method, lazy-initialised on first tab open
• Hash routing — every module has a linkable URL (#json, #jwt, …)
• State persistence — each module saves its last input and settings to localStorage under bofh:<module>:<key>. Wipe with the ⌫ button in the sidebar foot.
• Dark mode default, light mode toggle, follows prefers-color-scheme on first visit
• Web Crypto API for the JWT verifier — same primitives your OS uses, no JS crypto libraries
• Mobile-friendly — sidebar collapses to a hamburger menu

Keyboard shortcuts

• / — focus the module filter
• ? — open help
• Esc — close modal / blur input

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Run it

git clone https://github.com/NakliTechie/BOFH.git
cd BOFH
python3 -m http.server 8000
# open http://localhost:8000

Or just open index.html directly. Or drop it on any static host.

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Privacy

Your inputs are stored only in your own browser's localStorage. Nothing is sent over the network — there are zero fetch calls in Phase 1. The file is ~1300 lines of JS and ~50 KB total. Read it.

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Part of the NakliTechie series

Single-file, browser-native tools that don't phone home. Sister projects:

• BabelLocal — translator for 200 languages
• VoiceVault — Whisper transcription
• SnipLocal — background remover
• VaultMind — Obsidian explorer + AI chat
• NakliPoster — local-first API client
• KanZen — local-first kanban

Built by @NakliTechie.

License

MIT