I built a privacy-first developer toolbox — 50+ tools, all in your browser

Mike Sheldon — Mon, 16 Mar 2026 21:19:52 +0000

I built a privacy-first developer toolbox — 50+ tools, all in your browser
Like most developers, I constantly reach for small utility tools — format this JSON, decode that JWT, convert this timestamp. The problem: most of these sites are ad-heavy, slow, and quietly sending your data to a server somewhere.

So I built Here Be Tools — a fast, client-side dev toolbox where nothing ever leaves your browser.

What makes it different
100% client-side. Every tool runs entirely in your browser using native Web APIs and local JS libraries. No server requests for your data. No accounts. No tracking.

Works offline. Because there's no backend, it loads fast and keeps working even without a network connection.

Sensitive operations use Web Crypto. JWT signing, hashing, PEM decoding, and password generation all use the browser's built-in crypto API — meaning your secrets never touch a network.

What's in it
JSON — formatter, compare, schema validator, JSON→TypeScript, JSON→Zod, JSONPath tester

Convert — CSV↔JSON, JSON→YAML/XML/CSV, Markdown→HTML, TOML↔JSON, bytes/units

Encode — Base64, URL encode/decode, HTML/JS/JSON escape

Validate — JWT expiry, YAML, email, IP/CIDR, semver, URL inspector

Text — diff, case converter, line tools, word counter, slug generator, string inspector

Markup — HTML/CSS/JS formatter, XML formatter, Markdown preview, Markdown table builder, SOAP formatter

Developer — regex tester, cron parser, SQL formatter, timestamp, UUID generator, hash generator, chmod calculator, number base converter, Unicode inspector, JS playground, PEM decoder, GraphQL formatter, robots.txt generator

HTTP & Auth — JWT decoder/builder, cURL converter, cookie parser, HTTP headers analyzer, email headers parser, SPF/DMARC generator, user-agent parser

Utilities — color converter, CSV viewer, image→Base64, password generator, lorem ipsum, JS/CSS minifier

Under the hood
It's vanilla JS with ES modules — no framework. Built with Vite. Each tool is a single file that exports a render(container) function and is lazy-loaded on demand. The whole thing stays fast because there's no runtime framework overhead.

Try it
herebetools.com

Would love feedback — what tools are you missing? What's broken? Drop a comment below.

DEV Community: Mike Sheldon

I built a privacy-first developer toolbox — 50+ tools, all in your browser