Open source · No login · Free forever

A developer's console,
in your browser tab.

24 focused tools and 26 converters for formatting, encoding, validation and more. No installs. Nothing leaves your machine.

Explore all tools →Browse converters

devkult — ~/tools

$ devkult init

↳ mounting 24 tools…

✓ json · base64 · jwt · regex

✓ cron · uuid · sql · diff · dns

λ ready

$▌

01 / 04

Format & validate

Beautify minified JSON, validate against errors, format SQL, and reshape text lists — the everyday cleanup that starts most tasks.

02 / 04

Encode & secure

Base64 and URL transforms, JWT decoding, hashing, and bcrypt — the encoding and security primitives, all run locally.

03 / 04

Inspect & design

Preview HTML, test regex live, convert CSS units, check colour contrast, and look up DNS or WHOIS records.

04 / 04

Convert anything

And a long-tail of one-shot converters — px↔rem, JSON↔YAML, hex↔RGB, epoch↔date — each its own focused page.

$24 tools, 8 categories

{ }

Data & JSON

5 tools

JSON Formatter JSON Validator YAML ↔ JSON CSV ↔ JSON ↔ SQL SQL Formatter

⇄

Encoding

2 tools

Base64 Encode / Decode URL Encode / Decode

</>

Web

3 tools

HTML Viewer HTML Minifier HTTP Status Checker

🔐

Security

4 tools

JWT Decoder Hash Generator Bcrypt Tester UUID/ULID Generator

Regex

1 tool

Regex Tester

🎨

Design

3 tools

CSS Unit Converter Color Palette & Contrast SVG Optimizer

📝

Text & Workflow

4 tools

Diff Checker Crontab Explainer Markdown Previewer Text List Converter

🌐

Network

2 tools

DNS Lookup Whois Lookup

$Convert between formats

PX → REM JSON → YAML HEX → RGB Unix → Date CSV → JSON RGB → HEX all 26 →

Open a tool. Get back to building.

No accounts, no upsells, no telemetry on your data. Just fast utilities that run in the tab you already have open.

Explore all tools →