Password, hash, JWT and URL utilities that run entirely in your browser — no backend and no tracking.
- Node.js 24+ (Download)
- IDE (VS Code, WebStorm, ...)
- Package manager (pnpm (recommended), npm, ...)
- Optional: Docker (to run the app in a container)
- 12 tools in 5 categories — passwords & secrets, hashing, JWT, URLs and time
- Passwords & secrets — a password generator (strong, symbol-free or memorable) that reports the entropy of the result, a bit-length secret generator (hex + base64) for API keys and JWT secrets, and UUID v1, v4, v7, nil, GUID and CUID
- Hashing — bcrypt hashing and verification with a selectable cost factor and an explanation of what each one buys, plus MD5, SHA-1, SHA-256 and SHA-512 checksums computed all at once
- JWT — sign a header and payload into an HS256/HS384/HS512 token, or decode one and read its
claims, its
exp/iat/nbfas real dates and whether it has expired - URLs — a cleaner that strips tracking parameters (utm_*, fbclid, gclid, …) with a before / after diff and an aggressive mode, a percent-encoder / decoder and a slug generator
- Time — a Unix timestamp converter, both directions, in UTC and local time
- Privacy-first — everything runs in your browser, nothing is ever uploaded
- Logo page (
/logo) — download the app logo as a vector SVG - SEO ready — OpenGraph/Twitter cards with a generated OG image, JSON-LD, manifest, robots, sitemap
- Clone the repository and navigate to the root:
cd dev-toolkit/ - Install all dependencies:
pnpm install
- Development mode:
pnpm dev - Production mode:
pnpm build && pnpm start - Lint:
pnpm lint - Type check:
pnpm typecheck - Format:
pnpm format
The app ships a multi-stage Dockerfile (Next.js standalone output, non-root user) and a
docker-compose.yml.
cp .env.example .env # optional — defaults work for localhost
docker compose up -d --build # http://localhost:3000
docker compose logs -f dev-toolkit
docker compose downWithout compose:
docker build -t dev-toolkit --build-arg APP_URL=https://toolkit.ksprptr.dev .
docker run --rm -p 3000:3000 -e APP_URL=https://toolkit.ksprptr.dev dev-toolkitAPP_URL is inlined at build time — it feeds the prerendered canonical / OpenGraph / robots /
sitemap URLs and enables the Strict-Transport-Security header when it is an https:// origin — so
pass it as a build arg for any non-localhost deployment, and keep the runtime value identical.
Request headers (X-Forwarded-Host) are deliberately not trusted: they are client-supplied, and
honoring them would let anyone put a foreign domain into the app's own canonical/OpenGraph URLs.
The compose file binds the published port to 127.0.0.1 (the container is meant to sit behind a
reverse proxy on the same host); drop that prefix to expose it on the network directly.
| Description | Values |
|---|---|
| Port: | 3000 |
| Technologies: | Next.js, React, Tailwind CSS |
| URL: | http://localhost:3000 |
| Health check: | http://localhost:3000/api/health |
| Env: | APP_URL (public origin), APP_PORT (compose) |
This software is developed by Petr Kašpar and is licensed under the MIT License.
For more details, please refer to the LICENSE file.