Developer Tools, Finally Simple.

53+ free, instant-use utilities. No sign-ups, no installs. Just copy your data and go.

🚀 53+ Tools 🔒 100% Client-Side 💰 Forever Free

All Tools

📄

JSON Formatter

Prettify, minify, validate JSON with syntax highlighting

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🔄

JSON ↔ CSV

Convert between JSON and CSV formats instantly

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📊

JSON Diff

Compare two JSON objects and highlight differences

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📑

JSON ↔ XML

Convert JSON to XML and vice versa

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🔑

JWT Decoder

Decode JWT tokens without verification

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🔀

YAML ↔ JSON

Convert between YAML and JSON formats instantly

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📋

JSON Schema Generator

Generate JSON Schema from sample data. Auto-detect types and nested structures

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📘

JSON → TypeScript

Generate TypeScript interfaces from sample JSON payloads

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📰

XML Formatter

Pretty-print, minify, and validate XML in your browser

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🔤

Text Case Converter

Convert text to upper, lower, title, camelCase, snake_case

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📝

Diff Checker

Compare two texts and highlight the differences

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🔡

Lorem Ipsum Generator

Generate placeholder text for design mockups

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📋

Markdown Preview

Write Markdown and see it rendered in real time

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🔢

Word Counter

Count words, characters, lines, sentences, and reading time live

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🔍

Regex Tester

Test regular expressions against text with live match highlighting

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🌐

URL Encoder/Decoder

Encode or decode URL components for API work

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📧

HTML Entity Encoder/Decoder

Convert HTML entities to/from their character equivalents

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📱

Base64 Encode/Decode

Encode/decode data in Base64 format with length stats

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⚡

API Tester

Send HTTP requests and inspect responses with live timing

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↪️

cURL → fetch

Convert cURL commands into JavaScript fetch() snippets

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✅

HTML Validator

Check your HTML for common issues and syntax errors

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🌐

CIDR Subnet Calculator

Calculate network address, broadcast, and usable host range from any IP/CIDR

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📋

MIME Type Lookup

Search MIME types by name, extension, or category. Copy-paste ready

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🔗

CORS Policy Builder

Generate CORS headers for Nginx, Apache, Cloudflare, Express, and more

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🔍

Query String Parser

Parse and edit URL query parameters. Bulk editor with add/remove

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📱

QR Code Generator

Generate QR codes for URLs, WiFi, email, phone, and SMS

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🗃️

SQL Formatter

Beautify and minify SQL queries with syntax-aware formatting

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📧

Email Validator

Validate emails with syntax, domain, and disposable domain checks

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🎨

CSS Gradient Generator

Visual gradient designer with linear, radial, and conic support

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⚡

CSS/JS Minifier

Compress CSS, JavaScript, or HTML inline with compression ratio

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🐙

Git Command Generator

Generate git commands for branches, commits, rebase, stash, and more

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🎲

Dummy Data Generator

Generate fake names, emails, addresses, passwords, and test data in JSON/CSV/SQL

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🔐

chmod Calculator

Visual Unix permissions: build octal modes like 755 and 644

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🤖

AI Prompt Builder

Structure prompts with templates, system instructions, and parameter controls

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💰

API Cost Estimator

Estimate token usage and costs for GPT, Claude, Gemini, and other models

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🔢

Token Counter

Estimate token count and API costs for your text input across popular models

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🔐

JWT Generator

Create signed JWTs with custom headers, payloads, and secrets

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🎲

UUID Generator

Generate UUIDs (v4) for unique identifiers

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🔑

Password Generator

Generate secure, random passwords with strength meter

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#

Hash Generator

Generate SHA-256 and SHA-512 digests from text with Web Crypto

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🛡️

File Hash & VirusTotal

Hash files locally (SHA-256) and look up results on VirusTotal

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🎨

Hex/RGB/HSL Converter

Convert between Hex, RGB, and HSL color formats

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⏰

Unix Timestamp ↔ Date

Convert Unix timestamps to human-readable dates and vice versa

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⚙️

Cron Expression Parser

Convert cron expressions to human-readable descriptions

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🛠️

Cron Expression Builder

Build cron schedules with simple presets and custom fields

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🔢

Number Base Converter

Convert between binary, octal, decimal, and hexadecimal

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🖼️

SVG to PNG

Convert SVG vectors to PNG raster images with scaling options

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📦

PNG to SVG

Embed PNG images into SVG containers

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🏠

Mortgage Calculator

Calculate monthly payments, total interest, and full amortization schedule

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🚗

Auto Loan Calculator

Calculate monthly car payments with down payment and trade-in options

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🌍

WHOIS Lookup

Search domain registration info, registrar, nameservers, and expiry dates via RDAP

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🛰️

ARIN Network Lookup

Search IP ranges, ASN, network ownership, and abuse contacts via RDAP

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🔎

Domain Availability

Check if a domain is registered or available via RDAP WHOIS database

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Why DevToolBox?

⚡ Instant Use

No sign-ups, no installs. Paste your data and get results immediately.

🔒 100% Client-Side

Your data never leaves your browser. No servers, no cookies, no tracking.

💰 Forever Free

All tools are completely free. No premium tiers, no hidden fees.

Built for developers who care about privacy

Client-side first

Formatters, converters, generators, and crypto helpers run in your browser. Your payloads are not uploaded to DevToolBox servers for those tools.

No account wall

Open a tool and use it. No email gate for core utilities — ideal for quick fixes mid-debug.

Real documentation

Each tool includes how-to steps, use cases, and FAQ so you can learn the concept—not only click a button.

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