DevTools Pro: JSON formatter, API client, JWT, Base64/URL, timestamp, regex. Free, zero permissions, local-first.
Users
3
0 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#317K
#252K among extensions
Version
1.1.1
updated 14 Oct 2026
Users
monthly, 2 months
Latest, 15 Oct 2026:3 usersMove the mouse over the chart for any month
Ratings count
monthly, 2 months
Latest, 15 Oct 2026:0 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About DevTools Pro - Developer Toolbox
DevTools Pro is a free developer toolbox that puts 7 essential tools at your fingertips — a modern UI, zero permissions, and no data collection.
Every tool works right in the toolbar popup, and one click (⤢) expands it into its own floating window — no extra browser tab needed.
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🧰 TOOLS INCLUDED
1. JSON Formatter
• Parse & format with tree view (collapsible nodes)
• Deep search — find any key or value instantly
• Copy entire subtrees as JSON with one click
• Minify to single-line output
• Handles large files gracefully (progressive rendering)
2. API Client
• Send HTTP/HTTPS requests: method, URL, query params, headers, body
• Body types: JSON, text, x-www-form-urlencoded, form-data
• Response as Pretty / Raw / collapsible tree / headers, with status code, timing and size
• JSON editor with auto-closing brackets & quotes, and a tolerant repair pass that fixes unquoted values, missing commas and unclosed brackets
• Errors are underlined right in the text, plus a plain-language reason
• Pre-send checks flag anything the browser will silently change (forbidden headers, duplicate header keys, GET with a body)
• Requests go straight from your browser to the URL you enter — we have no server and never see them
3. JWT Encode / Decode
• Decode: Split header/payload/signature with expiry check
• Encode: HS256/384/512 signing via Web Crypto API
• 4 payload templates (Basic, Auth, Admin, API)
• Custom expiration: minutes, hours, days, or specific date
4. Timestamp Converter
• Unix seconds ↔ milliseconds auto-detection
• UTC + local time dual display with timezone info
• Real-time UTC + local clock
• One-click "Now" button
5. Regex Tester
• 7 built-in presets (email, URL, phone, IP, Chinese, etc.)
• 12 regex snippet buttons for quick insertion
• Real-time match highlighting with count
• Flag selector (g, i, m combinations)
6. Base64 Encode / Decode
• UTF-8 safe — handles Chinese and emoji
• Bidirectional encode ↔ decode
7. URL Encode / Decode
• Standard encodeURIComponent / decodeURIComponent
• One-click copy
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🔒 PRIVACY FIRST
• Zero permissions — the extension requests nothing
• No analytics, no tracking, no ads, no accounts
• Your data is never collected or stored: nothing is written to disk, and closing the page clears it
• The 6 converter tools run entirely on your device and make no network requests at all
• The API Client sends a request only when you click Send, directly from your browser to the address you typed. There is no server of ours in between — we cannot see, store or relay your requests
• Because no host permissions are requested, cross-origin API responses follow the browser's normal CORS rules: a response can be read only if the target server allows it
• Open privacy policy linked below
🌐 INTERNATIONAL
• Full English & Simplified Chinese support
• Auto-detects browser language
💡 PERFECT FOR
• Frontend/backend developers debugging APIs
• QA engineers inspecting JWT tokens
• DevOps engineers converting timestamps
• Anyone working with encoded data
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📬 Support: 13531021638@163.com