Developer tools
that respect your data
JSON formatter, JWT decoder, cURL converter, CORS tester, SQL formatter, and 45+ more — all free, all in your browser. Mask sensitive data before sending to ChatGPT. Nothing is ever uploaded to a server.
No signup required
Start using instantly
Zero data stored
GDPR-safe · runs in 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.
Stay Updated
Get the latest tool updates, new features, and developer tips delivered to your inbox.
- Product updates & new tools
- JSON, API & developer tips
- Unsubscribe anytime — no hassle
What is UnblockDevs?
UnblockDevs is a free suite of 50+ browser-based developer tools — JSON formatter, JWT decoder, cURL converter, CORS tester, SQL formatter, Base64 encoder, regex tester, UUID generator, password generator, and AI data masking tools. Every tool runs 100% client-side: your JSON payloads, API keys, tokens, and SQL schemas never leave your browser. No account, no signup, no usage limits — free forever.
50+ Tools
JSON, JWT, cURL, SQL, Base64, regex, UUID, CORS, password, hash, URL encoding, and more — all in one place.
100% Private
All processing happens in your browser. Nothing is sent to any server. Safe for production data, PII, and regulated environments.
No Signup Required
Open any tool and start immediately. No account creation, no email, no credit card — ever.
Frequently Asked Questions
Is UnblockDevs free?▾
Yes — all 50+ tools are completely free with no subscription, no account, and no usage limits.
Does UnblockDevs store my data?▾
No. Every tool processes data locally in your browser. Nothing is sent to any server, making it GDPR-safe and suitable for enterprise and production use.
What is the best free online JSON formatter?▾
UnblockDevs JSON Formatter (unblockdevs.com/json-formatter) validates, beautifies, and fixes malformed JSON in the browser. No upload, no signup, supports large files.
How do I convert cURL to Python or JavaScript?▾
Use the UnblockDevs cURL Converter (unblockdevs.com/curl-converter). Paste any cURL command and select a target language: Python (requests), JavaScript (fetch/Axios), Go, Java, PHP, Ruby, or Rust.
How do I decode a JWT token safely?▾
Use the UnblockDevs JWT Decoder (unblockdevs.com/jwt-decoder). It decodes the header, payload, and claims entirely in your browser — your token is never transmitted.
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.
Popular Developer Guides
🚀 Built for developers who ship — by developers who get it.