I built a free robots.txt generator & tester (no login, client-side)

Saravanan S — Mon, 30 Mar 2026 17:43:05 +0000

I built a free robots.txt tool that lets you:

• Generate robots.txt visually
• Validate syntax instantly
• Test if specific URLs are blocked or allowed

No login. No data upload. Everything runs in your browser.

👉 Try it: https://robotstxtgenerator.io

Would love feedback from developers and SEO folks 🙌

I built 180+ free browser-side developer tools — no login, no data uploads

Saravanan S — Wed, 18 Mar 2026 17:09:45 +0000

I got tired of having 12 different browser tabs open for developer tools.

One tab for JSON formatting. Another for Base64. One for regex testing.
One for JWT decoding. Another for converting that MySQL CLI output into
something readable...

So I built Devy Tools — 180+ free developer utilities in a single website.

The one thing that makes it different

Everything runs 100% in your browser.

No server. No data uploads. No account required. Your API keys, JWT tokens,
database output, and sensitive configs never leave your device — ever.

Most online tools quietly send your data to their servers. Devy Tools uses
the Web Crypto API and standard browser APIs to do all processing locally.
You can even use it offline after the first load.

What's inside

🗂️ Data Conversion

CSV ↔ JSON ↔ XML — bi-directional converters
CSV → HTML Table — paste CSV, get a styled table with 7 themes
JSON → HTML Table — supports arrays of objects, 2D arrays, single objects
XML → HTML Table — auto-detects repeating elements
MySQL CLI → HTML Table — paste the +----+------+ output directly
HTML Table → CSV / JSON / XML — scrape any web table and export it

🔐 Security & Cryptography

AES Encrypt / Decrypt
HMAC Generator
Bcrypt Hash Generator
SHA-256 / SHA-512
JWT Decoder

🔤 Encoding & Decoding

Base64 Encoder / Decoder
URL Encoder / Decoder
HTML Entity Encoder
Unicode Converter

⚙️ DevOps & Infrastructure

Dockerfile Generator
Docker Compose Generator
Kubernetes YAML Generator
.gitignore Generator
Cron Expression Builder

🤖 AI & LLM Tools

Token Counter
Prompt Template Builder
JSON to TypeScript Interface Generator
System Prompt Generator

🎨 CSS & Design

CSS Flexbox Generator
CSS Gradient Generator
CSS Box Shadow Generator
Color Contrast Checker

...and 130+ more tools across regex, SQL, networking, text processing,
and developer productivity.

The HTML Table tools are my favourite

The MySQL CLI → HTML Table converter is something I haven't seen done well
anywhere else. You copy-paste the raw terminal output:

+------+---------------+------------+---------+
| id | name | department | salary |
+------+---------------+------------+---------+
| 1 | Alice Chen | Engineering| 120000 |
| 2 | Bob Smith | Marketing | 85000 |
+------+---------------+------------+---------+

And you instantly get a styled, responsive HTML table with:

7 visual themes (Clean, Dark, Striped, Ocean, Sunset, Forest, Minimal)
Configurable header/data alignment
Hover highlighting
Responsive scroll for mobile
Download as a self-contained .html file

No library needed. No external CSS. Everything is inline.

Tech stack

React + Vite — fast SPA with lazy-loaded tool chunks
Web Crypto API — for AES, HMAC, SHA — all native, no libraries
DOMParser — for XML and HTML table parsing
Zero backend — static hosting, all logic in the client

What's coming

More language/framework-specific generators
Pro plan features: favourites, history, ad-free at pro.devy.tools
Blog with tool tutorials and use-case guides

Try it

👉 devy.tools

Everything is free. No signup. No catch.

If you find a tool missing, open the site and use the feedback button —
I'm actively adding new tools every week.

Built by Clinic Meet.

DEV Community: Saravanan S