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Free · No signup54+ tools · everything in your browser

Every dev tool you paste into Slack — in one tab

Format JSON, diff APIs, decode JWTs, generate UUIDs, hash passwords, and mask sensitive data before ChatGPT. No account. Nothing leaves your browser.

50+Free tools

100%Browser-side

ZeroData stored

FreeForever

AI Masking Preview

100% in-browser · nothing sent to servers

Sensitive — unsafe to share

SELECT * FROM user_orders WHERE customer_id = ? AND status = "active"

Masked — safe for AI

SELECT * FROM T_00001 WHERE C_00001 = ? AND C_00002 = "active"

AI Schema Masker

SQL schema safe for ChatGPT

Try AI Schema Masker

Trending

JSON workbench JSON formatter & beautifier JSON fixer & recovery JSON to Excel / CSV / Table Log unpacker & sanitizer cURL converter JWT decoder UUID / GUID generator

AI Safety

Mask before you prompt

AI schema masker

Mask SQL table & column names before ChatGPT — reversible.

Reversible maskTable & columnsChatGPT-safe

JSON prompt shield

Mask JSON keys and values before sending to any LLM.

Mask keysAny LLMReversible

Code prompt shield

Redact secrets and identifiers in code before Copilot / ChatGPT.

Redact secrets18 languagesCopilot-safe

Prompt chunker

Split long prompts for token limits — keep context clean.

Split promptsToken limitsCopy chunks

Just shipped

New tools

PDF to Excel & Word converter

Convert any PDF to Excel (

SVG to image

Convert SVG files to PNG or JPEG instantly, right in the browser

Cron Expression Builder

Build and explain cron expressions

Markdown Preview

Live GitHub Flavored Markdown editor and preview

Color picker & converter

Convert HEX ↔ RGB ↔ HSL ↔ CMYK instantly

Text & code diff checker

Compare two texts or files side-by-side

JSON & data16

JSON workbench

Viewer, tree, formatter, and JSON → Excel/CSV/Table on one page.

One-click formatMinify & validateClipboard copy

JSON formatter & beautifier

Format, minify, validate, and prettify JSON with one click.

One-click formatMinify & validateClipboard copy

JSON validator

Validate syntax and catch errors before production.

Syntax errorsSchema validationReal-time

JSON fixer & recovery

Repair malformed JSON, trailing commas, and AI-broken payloads.

Fix trailing commasAI-broken JSONAuto-recovery

JSON to Excel / CSV / Table

Convert nested JSON to spreadsheets — export XLSX or CSV in-browser.

Nested → XLSXCSV exportIn-browser

JSON Schema generator

Generate JSON Schema from sample data; validate structure.

Generate schemaValidate structureCopy JSON

Smart JSON diff

Semantic compare — normalizes UUIDs, JWTs, and timestamps.

Semantic diffSide-by-sideUUID normalize

JSON.stringify() online

Turn objects into JSON strings with pretty-print options.

Pretty-printEscape stringsCopy-ready

Log unpacker & sanitizer

Unescape nested JSON in logs, decode JWTs, scrub paths — client-side.

Nested JSON unescapeDecode JWTsScrub paths

Log explorer

Explore and navigate structured logs in the browser.

Browse logsFilter & searchNavigate easily

Payload analyzer

Inspect API payloads and structure without sending data to a server.

Inspect payloadsNo uploadDeep view

Data insights

Stats and patterns from JSON datasets — instant analysis.

Stats from JSONPattern detectInstant

SQL IN clause generator

Convert any list of IDs, emails, or UUIDs to a SQL IN clause. Auto-detect CSV, JSON, Excel paste. MySQL, PostgreSQL, Oracle, SQLite.

API response comparator

Diff two API JSON responses side by side.

Diff responsesSide-by-sideHighlight changes

Config comparator

Compare YAML/JSON configs and env-style files.

YAML/JSON configsEnv-file supportDiff view

JSON → TypeScript generator

Convert any JSON to TypeScript interfaces, type aliases, or Zod schemas — instantly.

API & HTTP7

cURL converter

Convert cURL to JavaScript, Python, fetch, and more.

JS/Python/fetchMulti-languageCopy-paste

cURL → Python

Turn cURL commands into Python requests code.

Python requestsFull headersInstant

HAR → cURL

Extract cURL from browser HAR exports.

Browser HARExtract cURLReplay requests

cURL failure analyzer

Diagnose TLS, DNS, proxy, and HTTP errors from cURL output.

TLS/DNS/proxyHTTP diagnosisRoot-cause

Mock API generator

Generate mock JSON APIs for front-end development.

Mock JSON APIsFront-end devInstant

Test data generator

Fake users, emails, UUIDs, and structured test fixtures.

Fake usersUUIDsStructured fixtures

CORS tester

Simulate preflight and real requests; read CORS headers.

Preflight simReal CORSPolicy check

Encode & crypto9

JWT decoder

Decode and verify JWTs; audit claims in-browser.

Decode & verifyAudit claimsNo upload

Encode & crypto

Base64 encoder / decoder

Standard, Base64URL, MIME; auto-detect JWT and images.

Base64/URLMIME detectAuto-detect JWT

Encode & crypto

UUID / GUID generator

v1–v8, bulk generate, validate, export JSON/CSV/SQL.

v1–v8 UUIDsBulk generateExport JSON

Encode & crypto

Hash generator

MD5, SHA-256, SHA3, HMAC, bcrypt, Argon2, file checksums.

MD5/SHA-256/SHA3HMAC/bcryptFile checksum

Encode & crypto

URL encoder / decoder

Encode query strings and path segments safely.

Encode stringsPath safeDecode instantly

Encode & crypto

Password generator

Random, passphrase, pattern modes; entropy and crack-time hints.

Entropy scorePassphraseCrack-time

Encode & crypto

Password audit

Strength checks and breach-aware guidance — locally.

Strength checkBreach hintsLocal only

Encode & crypto

Token comparator

Visual diff for JWTs, API tokens, and long strings.

Visual JWT diffAPI compareLong string

Encode & crypto

Image to Base64 converter

Convert PNG, JPG, SVG, GIF to Base64 data URIs. CSS, HTML img tag, and raw Base64 output.

Encode & crypto

Dev utilities18

PDF to Excel & Word converter

Convert any PDF to Excel (.xlsx) or Word (.docx). Smart table detection, heading recognition, multi-page support. 100% in-browser.

SQL IN clause generator

Convert any list of IDs, emails, or UUIDs to a SQL IN clause. Auto-detect CSV, JSON, Excel paste. MySQL, PostgreSQL, Oracle, SQLite.

Regex tester

Live match highlights, flags, and replace preview.

Live highlightsFlags supportReplace preview

Truth table generator

Boolean logic tables from expressions — export or copy.

Boolean tablesExpression inputExport

Speed test

Quick network latency and throughput checks in the browser.

Network latencyThroughputBrowser-based

Timezone translator

Convert timestamps across zones for debugging and deploys.

Convert timestampsMulti-zoneDeploy-friendly

SVG to image

Convert SVG files to PNG or JPEG instantly, right in the browser.

Cron Expression Builder

Build and explain cron expressions. See next run times and get human-readable schedules.

Markdown Preview

Live GitHub Flavored Markdown editor and preview. Copy HTML or download instantly.

Color picker & converter

Convert HEX ↔ RGB ↔ HSL ↔ CMYK instantly. WCAG contrast, Tailwind shades, and harmony palettes.

Text & code diff checker

Compare two texts or files side-by-side. Line and inline char diff, unified and split view.

Unix timestamp converter

Convert Unix epoch to readable dates in any timezone. Live clock, world clock, relative time.

CSS box shadow generator

Build beautiful multi-layer box shadows visually. 8 presets, live preview, instant CSS copy.

CSS gradient generator

Build linear, radial and conic CSS gradients visually. 15 presets, drag color stops, CSS & Tailwind output.

HTML formatter & minifier

Beautify messy HTML with custom indentation, or minify for production. Shows size savings.

HTML viewer & live editor

Live HTML/CSS/JS sandbox. Write code and see it render instantly in a safe iframe preview.

HTTP headers analyzer

Paste HTTP response headers and get an A+ to F security grade. Checks CSP, HSTS, CORS and generates Express/Nginx/Apache config.

String utilities

All 12 case formats simultaneously (camelCase, snake_case, PascalCase…), extract emails/URLs/IPs, Base64/URL/HTML encode, line tools.

All 54+ tools — free, forever

No signup, no paywall. Everything runs entirely in your browser.

No accountZero data storedFree foreverOpen instantly

Back to JSON workbench

Frequently asked questions

Are these developer tools free?: Yes. The full directory of 54+ utilities is free and does not require an account.
Does my data leave my device?: Core tools process input in your browser. Do not paste truly secret production credentials into any online tool if your security policy forbids it — but UnblockDevs does not receive your payloads for those client-side tools.
Which tool should I use for ChatGPT and JSON?: For SQL schemas use AI Schema Masker. For arbitrary JSON use JSON Prompt Shield. Both support reversible masking so you can map answers back to real names later.
Where can I learn more about JSON best practices?: See our JSON best practices guide and JSON viewer & formatter guide.