JSON and data
Format, validate, minify, compare and convert structured data for APIs, configuration files and application workflows.
Explore JSON and data tools →Ctrl K
Explore Tools → DEVUTILITYKITS · 150+ · 100% FREE ONLINE TOOLS
Free Online Developer Tools
for JSON, SEO, Coding, Images & More.
150+ fast utilities for the small jobs developers do every day: format JSON, decode JWTs, test regex, check DNS and headers, generate configs, and convert images and data. No signup, and many tools run right in your browser.
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View all tools →Popular Online Developer Tools
The tools people reach for most: JSON formatting and validation, Base64 and URL encoding, JWT decoding, UUIDs, hashes, regex testing and SQL formatting.
JSON Formatter
↗Format, beautify, and validate JSON online with this free JSON formatter. Improve readability and inspect structured data for APIs and configuration files.
JSON Validator
↗Validate JSON online to detect syntax errors, missing commas, invalid quotes, and malformed data. Check JSON for free before using it in your projects.
JSON Minifier
↗Minify JSON online by removing unnecessary whitespace and formatting. Create compact JSON for APIs, applications, and data transfer with this free tool.
JSON Browser CLI
↗Run JSON CLI commands online to format, validate, minify, compare, query, and transform JSON in your browser. Free, with no CLI installation required.
Base64 Encoder / Decoder
↗Encode text to Base64 or decode Base64 strings online for free. Convert data for APIs, web development, debugging, and everyday encoding tasks.
URL Encoder / Decoder
↗Encode or decode URLs and query parameters online. Convert special characters to URL-encoded format for APIs, web development, and HTTP requests.
UUID Generator
↗Generate random UUIDs online free. Create unique identifiers for applications, databases, APIs, sessions, testing, and software development.
JWT Decoder
↗Decode JWT tokens online and inspect their headers and payload claims. View JSON Web Token data directly in your browser with this free tool.
Hash Generator
↗Generate cryptographic hashes from text online using supported hashing algorithms. Create hash values for development, testing, and data integrity checks.
Regex Tester
↗Test regular expressions online. Check pattern matches against sample text and troubleshoot regex syntax with this free regular expression tester.
SQL Formatter
↗Format SQL queries online with readable indentation and organized clauses. Clean up database queries for debugging and code reviews.
Image Converter
↗Convert images between popular formats, including JPEG, JPG, PNG and WebP, with a free online image converter for websites, design and everyday use.
JSON WORKFLOW
JSON CLI Online for Formatting, Validation, and Data Processing
Run JSON commands in your browser with no install. Format, validate, minify, query, sort, compare and transform JSON using a command-line-style interface, for example get user.profile.name or sort-keys.
It’s handy for debugging API responses, cleaning up structured data, or preparing JSON for an application.
json> format --pretty
json> validate --verbose
json> get user.profile.name
json> sort-keys --download
json> diff
Browser-based processing · no installation requiredEXPLORE
Developer Tools Organized Around Your Workflow
Browse 14 categories, from JSON and data conversion to SEO, DNS, security, Cloud/DevOps and image processing. Open a category to see every tool in it, or use the search box (Ctrl K) to jump straight to one.
Web Generators
↗Generate QR codes, robots.txt files, sitemaps, favicons, server configurations, and security headers with free online web generator tools.
8 toolsCloud/DevOps
↗Explore free Cloud and DevOps utilities for Docker, Kubernetes, Git, Linux, CI/CD, networking, and common configuration tasks.
20 toolsTime Tools
↗Convert Unix timestamps, calculate date differences, check time zones, and work with durations and business days using free online time tools.
8 toolsCalculators
↗Calculate percentages, ratios, dates, units, storage, and more with free online calculators for quick answers to everyday questions.
14 toolsSEO Tools
↗Improve technical and on-page SEO with free tools for meta tags, structured data, URLs, redirects, robots.txt, and website crawl directives.
15 toolsMarketing Tools
↗Create UTM campaign URLs, social sharing metadata, business cards, and structured data with free online marketing tools for digital campaigns.
7 toolsJSON & Data
↗Format, validate, minify, compare, sort, and convert JSON and structured data with free online tools for development and data workflows.
12 toolsEncoding & Conversion
↗Encode, decode, and convert common text and data formats with free online utilities for web development, data exchange, and troubleshooting.
7 toolsSecurity & Identity
↗Generate UUIDs, inspect JWTs, calculate supported hashes, and use practical security and identity utilities online for everyday development tasks.
7 toolsCode & Formatting
↗Format, beautify, minify, and compare HTML, CSS, JavaScript, SQL, and other supported code with free online developer tools.
10 toolsText Tools
↗Count words and characters, clean text, remove duplicate lines, change case, sort lines, and compare text with free online text tools.
10 toolsDeveloper Utilities
↗Find free online developer utilities for testing, troubleshooting, data handling, and routine coding and website maintenance tasks.
6 toolsDNS & Website Tools
↗Troubleshoot domain and website issues with online free tools for DNS records, email authentication, domain checks, and web configuration.
11 toolsImage Tools
↗Convert, resize, compress, and analyze images with online free image tools for common formats, websites, documents, and everyday projects.
34 toolsBUILT FOR REAL WORKOne toolkit.
One toolkit.
Hundreds of tiny problems solved.
JSONBase64JWTUUIDRegexDNSSQLURLHashImagesYAMLHTTP
WHY DEVUTILITYKITS
Simple Tools. Less Friction.
Each tool does one job, explains how to use it, and links to related tools for the next step, so a small task stays small.
⚡
Fast and Easy to Use
Focused interfaces and clear workflows help you complete everyday technical tasks with fewer unnecessary steps.
🔒
Privacy-Conscious Tools
Tools that support local processing let you work with data directly in your browser without uploading it to a server.
◎
No Account Required
Access everyday utilities without creating an account or going through a registration process.
⌘
Built for Developers
Practical utilities for coding, APIs, JSON, web development, DNS, SEO, and data conversion workflows.
ALL TOOLS
Explore All Developer Tools
Browse 150+ free online developer tools by category, from JSON and data conversion to SEO, security, DNS, Cloud/DevOps and image processing. Each tool does one job, runs in your browser and needs no account.
🛠️Web Generators
☁️Cloud/DevOps
Docker Compose Generator→Dockerfile Generator→Docker Command Generator→Kubernetes YAML Generator→Kubernetes Resource Calculator→Gitignore Generator→Git Command Generator→Cron Parser→Chmod Calculator→Linux Command Generator→Systemd Service Generator→Environment Variable Generator→CI/CD YAML Generator→GitHub Actions Generator→GitLab CI Generator→IP Subnet Calculator→CIDR Calculator→IPv4 Converter→IPv6 Converter→DNS Record Generator→
⏰Time Tools
🧮Calculators
🔎SEO Tools
Robots.txt Generator→Sitemap Generator→Canonical URL Generator→Schema Generator→Product Schema Generator→Local Business Schema Generator→FAQ Schema Generator→Breadcrumb Schema Generator→Keyword Density Checker→SERP Snippet Preview→Redirect Checker→URL Analyzer→Sitemap URL Extractor→Robots.txt Tester→Meta Description Generator→
📣Marketing Tools
🗂️JSON & Data
🔄Encoding & Conversion
🛡️Security & Identity
💻Code & Formatting
📝Text Tools
⚙️Developer Utilities
🌐DNS & Website Tools
🖼️Image Tools
Image Converter→JPG to PNG→PNG to JPG→SVG to PNG→PNG to SVG→WebP Converter→Image Resizer→Image Compressor→Image Cropper→Image Rotator→Image to Base64→Base64 to Image→Image Color Picker→Image Metadata Viewer→EXIF Viewer→EXIF Remover→Image DPI Calculator→Image Aspect Ratio Calculator→Favicon Generator→ICO Converter→Screenshot Cropper→Blur Image→Pixelate Image→Grayscale Image→Image Border Generator→Image Watermark→Image Background Remover→Social Image Resizer→YouTube Thumbnail Downloader→Instagram Image Resizer→Facebook Image Resizer→LinkedIn Image Resizer→Image Size Calculator→Placeholder Image Generator→
DEVELOPER RESOURCES
Practical Online Tools for the Everyday Tasks That Slow Development Down
DevUtilityKits puts 150+ free online developer tools in one place, so you don’t need a different site for each small job. Format and validate JSON, decode Base64 or JWTs, test regular expressions, check HTTP headers and DNS records, generate Docker and Kubernetes configs, or resize and compress images.
Whether you’re building websites, debugging an API or checking technical SEO with tools like the robots.txt tester and schema generators, each tool does one job and links to related ones. Many run in your browser with nothing to install, and tools that support local processing keep your input on your device.
New to a problem? Our developer problem-solving guides walk through common issues and point you to the right tool.
Encoding and conversion
Encode and decode Base64, URLs and other common representations when working with APIs, web applications and data interchange.
Explore encoding tools →SEO and web development
Generate metadata and structured web elements, inspect domains and work through practical technical SEO and website configuration tasks.
Explore SEO tools →Images and media
Resize, compress, convert and optimize common image formats for websites, documentation, applications and content workflows.
Explore image tools →Security and infrastructure
Work with hashes, JWTs, UUIDs, DNS, HTTP, Docker, Kubernetes, Linux and other everyday infrastructure tasks.
Explore security tools →Calculators and time tools
Handle percentages, ratios, units, storage, dates, timestamps, durations and business-day calculations without a spreadsheet.
Explore calculators →Built for Developers, Webmasters, and Technical Teams
Every web project involves small technical tasks: formatting a JSON response, decoding Base64, testing a regular expression, inspecting HTTP headers, or checking DNS records. DevUtilityKits puts 150+ free online developer tools in one place, so you don’t have to search for a separate utility each time.
The collection covers JSON and data conversion, SEO and website diagnostics, code formatting and generation, security utilities, image tools, and Cloud/DevOps configuration. Each tool focuses on one task and links to related tools for the next step in your workflow.
Many tools run directly in your browser with no installation. Where a tool supports local processing, your input stays on your device instead of being uploaded to a server.
If you’re debugging a specific problem, our developer problem-solving guides walk through common issues and point you to the right tool.
FAQ
Frequently asked questions
Are DevUtilityKits tools free?
Yes. The core online utilities are designed to be free to use.
Do I need an account?
No account is required for normal use of the tools.
Is my data uploaded?
Tools that support client-side processing can process your input directly in your browser. Check the individual tool for its processing behavior.
Can I use the tools on mobile?
Yes. The site is designed to work across desktop, tablet and mobile screens.