DevTools

Developer Tools, instantly in your browser

Privacy-first tools that run 100% locally. No login, no uploads, no tracking. Just open and use.

Open Smart ChecklistBrowse Tools
Runs locally
No signup
Privacy-first
Free forever
release-checklist
2/5 complete40%
  • Deploy database migrations
  • Run smoke tests
  • Update release notes
  • Notify stakeholders
  • Archive old builds
cron-generator
Minute
0
Hour
9
Day
*
Month
*
Weekday
1-5

Expression

0 9 * * 1-5

Meaning

At 9:00 AM, Monday through Friday

regex-tester

Pattern

/\d+/g

Test string

Deploy v2.14 on port 8080
2 matches

All Tools

Click any tool to open it instantly. No loading screens.

Smart Checklist

Featured
Open

Convert any text into an interactive checklist. Drag-and-drop reorder, 3-state toggles, PDF export, and shareable URLs.

release checklistQA checklistdeveloper checklist

JSON Formatter

Prettify, minify, validate and explore JSON with syntax highlighting.

json beautifierjson validator

Cron Generator

Build cron expressions visually. Supports Unix, AWS EventBridge and Spring.

cron buildercron parser

Diff Checker

Compare text side-by-side with line, character and JSON-aware diffing.

compare textjson diff

JWT Decoder

Decode JWT tokens and inspect claims without sending tokens anywhere.

decode jwtjwt inspector

Regex Tester

Test regular expressions live with match highlighting and replace preview.

regex checkerregex validator

Why DevTools Suite?

Built for developers who value speed, privacy, and focus over feature bloat.

Your data never leaves your device

Every tool runs entirely in your browser using JavaScript. No file uploads, no API calls, no server processing. JWT tokens, JSON payloads, and diff content stay on your machine.

Faster than AI chat workflows

Open a tool, paste your content, get your result — in under a second. No prompting, no waiting for a model response, no copy-paste round trips.

Works offline after first load

Once the page loads, the tools work without an internet connection. Ideal for working in restricted environments, on flights, or with a spotty connection.

Built for keyboard-first developers

Every tool supports keyboard shortcuts, tab navigation, and accessible interactions. Designed for developers who prefer the keyboard over the mouse.

Frequently Asked Questions

Are all tools completely free?
Yes. Every tool in DevTools Suite is free to use with no limits, no rate limits, and no premium tier. We sustain the platform through minimal, non-intrusive advertising.
Is my data uploaded to your servers?
No. All processing happens locally in your browser. We have no backend, no database, and no server that receives your content. Your JSON, tokens, regex patterns, and checklist items never leave your device.
Do the tools work offline?
Yes. After the initial page load, all tools function without an internet connection. The only features that require connectivity are AdSense ads and Google Analytics — both of which are non-essential.
Is login or an account required?
No. There are no accounts, no sign-up forms, and no email required. Open any tool and start using it immediately.
Do the tools work on mobile?
Yes. All tools are responsive and tested at 375px viewport width. Toolbars adapt to mobile layouts, and touch interactions are supported throughout.
How is my checklist saved between sessions?
The Smart Checklist saves your work to your browser's localStorage automatically. No account needed — your list is there when you come back, as long as you use the same browser.