Developer tools
that respect your data
50+ free browser-based tools for JSON, SQL, APIs, AI, color, diff, and CSS. Mask sensitive data before sending to ChatGPT. Format, debug, and convert — all without uploading anything to a server.
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Zero data stored
100% runs in your browser
Free forever
No hidden fees, ever
AI Schema Masker
100% client-side · free
What are you working on?
55 tools · free forever› format · decode · convert · debug · generate · compare
AI Schema Masker
Mask SQL/JSON schema before ChatGPT. Fully reversible in one click.
- GDPR & HIPAA safe
- Deterministic mapping
- Works offline
JSON Prompt Shield
Mask JSON keys & values before AI. Keys→K_00001, strings→S_00001.
- Preserve structure
- Batch masking
- Instant restore
Code Prompt Shield
Mask API keys, variable names & secrets before Copilot or ChatGPT.
- 18 languages
- Pre-scan risk
- Custom patterns
JSON Formatter
HOTBeautify & indent JSON
JSON Beautifier
Pretty-print with syntax color
JSON Validator
Check syntax & structure instantly
JSON Fixer
Auto-repair broken JSON
AI JSON Fixer
AIAI explains & fixes every error
JSON Comparator
Diff & highlight two JSON objects
JSON → TypeScript
NEWGenerate TS types from any JSON
JSON Schema Gen
Build JSON Schema from a sample
JSON Stringify
Stringify & escape JSON strings
JSON to Excel
Export JSON rows to .xlsx
Text Diff
NEWDiff any two blocks of text
SQL Formatter
HOTBeautify & indent SQL queries
SQL IN Generator
NEWBuild IN (val, val, …) lists fast
JWT Decoder
Decode & inspect JWT tokens
Token Compare
Spot differences between tokens
Hash Generator
MD5, SHA-256, bcrypt & more
Password Gen
Generate strong secure passwords
Password Audit
NEWScore & audit password strength
Base64 Encoder
Encode & decode Base64 strings
URL Encoder
Encode & decode URL components
Image → Base64
NEWConvert images to data URIs
UUID Generator
Generate v4 UUIDs instantly
cURL Converter
Convert cURL to 10+ languages
HAR to cURL
Replay browser requests as cURL
cURL Analyzer
AI diagnoses cURL failures
CORS Tester
Test CORS headers live
HTTP Headers
NEWAnalyze HTTP response headers
API Comparator
Diff two API responses side-by-side
Config Compare
Diff JSON / YAML config files
Payload Analyzer
Inspect & profile API payloads
Mock API
Generate mock JSON responses
Test Data Gen
Realistic fake data for testing
AI Schema Masker
AIMask schema before ChatGPT
JSON Prompt Shield
AIMask JSON keys before sending to AI
Code Prompt Shield
AIHide secrets before Copilot
Data Insights
NEWAI analysis of any data
Log Explorer
Parse & search structured logs
Log Unpacker
Decompress & decode log bundles
Prompt Chunker
AISplit prompts by token budget
Regex Tester
Live regex test & explanation
Timestamp
NEWConvert Unix ↔ human-readable time
Timezone
Translate times across zones
Cron Builder
NEWBuild & decode cron expressions
Truth Table
Generate logic truth tables
Markdown Preview
NEWLive Markdown → HTML preview
String Utilities
Trim, case, encode & transform
Speed Test
Test your browser download speed
HTML Formatter
NEWBeautify & indent HTML markup
HTML Viewer
NEWRender & preview HTML live
Box Shadow
NEWCSS box-shadow visual builder
CSS Gradients
HOTVisual CSS gradient builder
Color Picker
NEWPick, convert & export colors
SVG to Image
NEWExport SVG as PNG or JPEG
Image to Text
NEWOCR: extract text from images
PDF to Excel
NEWExtract tables from PDF files
Fast. Private. No account needed.
All tools run entirely in your browser — zero server round-trips, zero data exposure.
Find your tool
Search or browse by category. Every tool is one click away — no accounts, no ads blocking your path.
Paste your data
Paste JSON, SQL, cURL, tokens, code — whatever you need. Nothing leaves your device at any point.
Get your result
Tools process locally in milliseconds. Copy, download, or use the output directly.
Discover more
Every tool page shows related tools. One tab, zero friction — bookmark and come back anytime.
Your data never touches our servers
Every single tool on UnblockDevs runs entirely in your browser. We don't have servers that process your data — because we don't need them.
Try AI Schema MaskerNo server-side processing
All computation happens in your browser using JavaScript. No request is made to our backend.
No logging or telemetry
We don't log your SQL schemas, JSON payloads, API keys, or any other sensitive input.
GDPR, HIPAA, SOC 2 safe
Suitable for regulated industries. Nothing is shared with third parties, ever.
Open architecture
Built with Next.js. Inspect every network request and verify no data leaves your device.
Guides for developers
How to use AI coding tools in healthcare without violating compliance requirements.
8 min readAPI DebuggingWhy Your API Works in Postman but Not in cURL — 7 ReasonsThe most common causes of this frustration and the exact fix for each scenario.
6 min readJavaScriptJSON.stringify Complete Guide — Undefined, Circular References, and Edge CasesEverything JSON.stringify does that surprises developers, with examples for every edge case.
7 min readShare Your Feedback
Tell us what's working, what's broken, or what you wish we built next — it directly shapes our roadmap.
Good feedback is gold — a rough edge you hit today could be smoother for everyone tomorrow.
- Feature ideas often jump the queue when lots of you ask.
- Bug reports with steps get fixed faster — paste URLs or examples if you can.
- Name and email are optional; we won't use them for anything except replying if needed.
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UnblockDevs — Free Online Developer Tools Suite
JSON Viewer, Formatter, Parser, Beautifier, Fixer, JSON to Excel/CSV, API testing, schema generation, SQL formatting, log analysis, and more. All tools are free and run in your browser.
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