DevBolt
DevBolt is a privacy-focused collection of 117 free developer tools that run entirely in the browser — no uploads, no accounts, no telemetry. Categories span formatting, conversion, generation, inspection, and interactive playgrounds.
Developer Tools(51)
.env File Validator
Validates .env files for syntax errors, duplicate keys, security risks, and .env.example export.
.env to Docker/K8s Converter
Converts .env files to Docker Compose env blocks, Kubernetes ConfigMaps, and docker run flags.
.gitignore Generator
Generates .gitignore files from 50+ templates across major languages and ecosystems.
AI Model Comparison
Compares 23 AI models and 5 coding IDEs — pricing, context windows, capabilities.
AI Prompt Builder
Builds structured AI prompts with templates and variables for OpenAI, Anthropic, and Gemini.
Code Complexity Analyzer
Measures cyclomatic complexity, cognitive complexity, nesting depth, and maintainability index.
Code Screenshot Generator
Creates code screenshots with 8 themes, syntax highlighting, and customisable backgrounds.
Compression Tester
Compares Brotli, Gzip, and Deflate compression ratios for text content.
Cron Expression Parser
Parses cron schedules into plain English with the next several scheduled run times.
Crontab Generator
Builds cron expressions visually with frequency, time, and day-of-week controls.
Docker Compose Validator
Validates and formats Docker Compose files, checking services, networks, and volumes.
Dockerfile Validator
Validates and lints Dockerfiles for syntax errors, security issues, and best practices.
ESLint to Biome Converter
Converts ESLint configs to Biome — maps 100+ rules from core, TypeScript, React, and import plugins.
Git Command Builder
Builds git commands visually with 80+ cheat-sheet entries covering branching, merging, and stashing.
Git Diff Viewer
Renders unified git diff output with syntax highlighting and side-by-side or inline display.
GitHub Actions Validator
Validates GitHub Actions workflow YAML for syntax, triggers, jobs, and deprecated actions.
GraphQL to TypeScript
Converts GraphQL SDL schemas to TypeScript interfaces, types, enums, and operations.
HTTP Status Codes Reference
Complete reference of HTTP status codes with explanations, common causes, and use cases.
JSON Formatter
Formats, validates, and minifies JSON with structural error reporting.
JSON Mock Data Generator
Generates realistic fake JSON data for API testing with 30+ field types and schema builder.
JSON Visualizer
Visualises JSON as an interactive tree — collapsible nodes, search, path copy, and stats.
JSON to Code Generator
Generates typed structs and classes from JSON in Go, Python, Java, C#, Dart, Rust, Swift, and Kotlin.
JSON to GraphQL Schema
Generates GraphQL schema definitions from JSON with type inference and Query/Mutation generation.
JSON to Zod Converter
Converts JSON or JSON Schema to Zod validation schemas with $ref resolution and format constraints.
JavaScript / TypeScript Playground
Runs JavaScript and TypeScript code in the browser with instant console output.
Kubernetes YAML Validator
Validates Kubernetes manifests for syntax, required fields, best practices, and security.
LLM Token Counter
Counts tokens and estimates API costs for GPT, Claude, Gemini, and other LLMs.
MCP Config Builder
Builds MCP configuration files visually for Claude Desktop, Cursor, VS Code, and Windsurf.
Markdown Preview
Writes and previews Markdown with live rendering and syntax highlighting.
Markdown Table Generator
Builds Markdown tables visually with CSV import and alignment controls.
Nginx Config Generator
Generates nginx config files — server blocks, SSL, reverse proxy, gzip, load balancing, security headers.
Number Base Converter
Converts numbers between binary, octal, decimal, and hexadecimal bases.
Open Graph Preview
Previews and debugs Open Graph, Twitter Card, and SEO meta tags for social sharing.
OpenAPI to TypeScript
Converts OpenAPI 3.x and Swagger 2.0 specs to TypeScript interfaces and operation types.
QR Code Generator
Generates customisable QR codes from text or URLs.
README Generator
Generates professional GitHub README.md files with badges, installation, and usage sections.
Regex Generator
Generates regex patterns from natural-language descriptions with visual composer and live tester.
SQL Playground
Runs SQL queries against a WebAssembly SQLite database — JOINs, CTEs, window functions, aggregations.
SQL to TypeScript / Prisma / Drizzle
Converts SQL CREATE TABLE statements to TypeScript interfaces, Prisma schemas, and Drizzle definitions.
SVG to JSX Converter
Converts SVG to JSX or a React/TypeScript component with forwardRef, memo, and props spread.
TypeScript 6.0 Migration Checker
Analyses tsconfig.json for TS 6.0 breaking changes, deprecated options, and readiness grade.
TypeScript to JavaScript
Strips TypeScript types, interfaces, enums, and generics to produce clean JS output.
URL Encoder & Decoder
Encodes and decodes URLs using encodeURIComponent and encodeURI.
URL Parser
Parses URLs into protocol, host, path, and query-string components.
URL Slug Generator
Converts text into URL-friendly slugs with Unicode transliteration and bulk mode.
XML Formatter
Formats, beautifies, validates, and minifies XML documents.
Zod Schema Generator
Generates Zod validation schemas from JSON with auto-detection of common formats.
cURL to Code
Converts cURL commands to JavaScript, Python, Go, PHP, Ruby, and Java code.
package.json Generator
Generates package.json visually with framework presets, dependency editor, and scripts.
robots.txt Generator
Generates robots.txt files with crawl rules for Googlebot, Bingbot, AI bots, and more.
tsconfig.json Builder
Builds TypeScript tsconfig.json visually with framework presets and inline explanations.
HTML & CSS Tools(16)
Border Radius Generator
Designs CSS border-radius visually with per-corner controls and unit selection.
Box Shadow Generator
Designs CSS box shadows visually with multi-layer stacking and live preview.
CSS Animation Generator
Builds CSS keyframe animations visually with presets and live preview.
CSS Clip-path Generator
Creates CSS clip-path shapes visually with 13 shape presets and interactive preview.
CSS Filter Generator
Builds CSS filter effects visually — blur, brightness, contrast, hue-rotate, sepia, drop-shadow.
CSS Gradient Generator
Creates CSS gradients visually with live preview and copy-paste output.
CSS Unit Converter
Converts between px, rem, em, pt, vw, vh, and % single values or batch CSS files.
CSS to Tailwind Converter
Converts CSS to Tailwind utility classes across 100+ properties.
Favicon Generator
Generates favicons from text or emoji — PNG, SVG, Apple Touch Icon, and HTML output.
Flexbox Generator
Builds CSS flexbox layouts visually with live preview and component presets.
Grid Generator
Builds CSS grid layouts visually with column, row, and gap controls.
HTML Table Generator
Builds HTML tables visually with rows, columns, headers, captions, and inline-CSS or Tailwind output.
Meta Tag Generator
Generates SEO, Open Graph, and Twitter Card meta tags with live previews.
Tailwind CSS Generator
Builds Tailwind utility classes visually with live preview and component presets.
Tailwind to CSS Converter
Converts Tailwind utility classes to standard CSS — 500+ classes including arbitrary values.
Text Shadow Generator
Designs CSS text shadows visually with multi-layer stacking and presets.
Security(11)
AI Code Security Scanner
Scans JavaScript and TypeScript for hardcoded secrets, injection, XSS, SSRF, and 20+ vulnerability checks.
CSP Header Builder
Builds Content Security Policy headers visually with framework presets and security analysis.
File Hash Calculator
Computes MD5, SHA-1, SHA-256, SHA-384, and SHA-512 file hashes via drag-and-drop.
HTTP Request Builder
Builds HTTP requests visually and generates client code in cURL, JavaScript, Python, Go, Rust, and PHP.
Hash Generator
Generates SHA-1, SHA-256, SHA-384, and SHA-512 hashes of input text.
JWT Builder
Builds and signs JSON Web Tokens with HMAC, RSA, and ECDSA algorithms.
JWT Decoder
Decodes and inspects JSON Web Tokens, surfacing header, payload, and signature.
Password Generator
Generates strong, secure random passwords with configurable character classes.
Regex Tester
Tests regular expressions with real-time match highlighting and capture-group inspection.
Security Headers Generator
Generates HTTP security headers for Nginx, Apache, Vercel, Netlify, and Cloudflare with scoring.
UUID Generator
Generates random UUID v4 identifiers in bulk.
Data Format Converters(9)
CSV ↔ JSON Converter
Converts between CSV and JSON with custom delimiters and column handling.
HTML to JSX Converter
Converts HTML to JSX — class→className, inline styles to objects, self-closing tags, SVG attributes.
HTML ↔ Markdown
Converts between HTML and Markdown bidirectionally.
JSON to CSV Converter
Converts JSON arrays to CSV with nested-object flattening and column selection.
JSON to SQL Converter
Converts JSON arrays to SQL CREATE TABLE and INSERT statements with type inference.
JSON to TypeScript
Generates TypeScript interfaces and type aliases from JSON data.
JSON ↔ XML Converter
Converts JSON to XML and XML to JSON with attribute and CDATA support.
JSON ↔ YAML Converter
Converts between JSON and YAML — ideal for Kubernetes, Docker, and CI/CD configs.
TOML ↔ JSON/YAML Converter
Converts between TOML, JSON, and YAML — perfect for Cargo.toml and pyproject.toml.
Code Formatters & Validators(8)
Code Minifier & Beautifier
Minifies and beautifies JavaScript, CSS, and HTML code.
JSON Diff
Compares two JSON objects and reports structural differences with key-level granularity.
JSON Path Tester
Tests JSONPath expressions against JSON data with real-time evaluation.
JSON Schema Validator
Validates JSON data against JSON Schema (Draft 07) with detailed error reporting.
OpenAPI / Swagger Validator
Validates OpenAPI 3.x and Swagger 2.0 specs for structure, schemas, security, and best practices.
SQL Formatter
Formats, beautifies, and minifies SQL queries across major dialects.
XPath Tester
Tests XPath expressions against XML data with real-time evaluation and axis navigation.
YAML Formatter
Validates, formats, beautifies, and minifies YAML documents.
Encoders & Decoders(5)
Base64 Codec
Encodes and decodes Base64 strings with Unicode support.
Encode / Decode Multi-Tool
Base64, Base32, Hex, Binary, URL, and HTML encoding and decoding in one tool.
HTML Entity Encoder
Encodes and decodes HTML entities, special characters, and symbols.
Image to Base64
Converts images to Base64 data URIs and decodes Base64 back to images.
Text ↔ Binary Converter
Converts text to binary, hex, octal, or decimal — with UTF-8 round-trip.