241+ developer tools · all private, all free

Every developer tool you need, in one place

Format, convert, validate, encode and generate — JSON, YAML, code editors, time zones and more. No uploads, no accounts. Everything runs locally in your browser.

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241+: free tools
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Converters

101

Convert between JSON, XML, YAML, TOML, CSV, generate code & convert images, SVG, Markdown & styles

CSV to JSONConvert CSV rows into a JSON array of objects.CSV to XMLConvert CSV rows into structured XML records.CSV to YAMLConvert CSV rows into a clean YAML sequence of objects.CSV to JSON SchemaGenerate a JSON Schema from CSV columns with inferred property types.CSV to TypeScriptGenerate a typed TypeScript interface from CSV columns.CSV to GoGenerate a typed Go struct from CSV columns.CSV to PydanticGenerate a typed Pydantic model from CSV columns.Color ConverterConvert colors between HEX, RGB, HSL and more.XML to JSONConvert XML to JSON instantly in your browser.TOML to JSONConvert TOML config to JSON instantly in your browser.YAML to JSONConvert YAML config to JSON instantly in your browser.JSON to XMLConvert JSON to well-formed XML.TOML to XMLConvert TOML config to well-formed XML.YAML to XMLConvert YAML to well-formed XML.JSON to CSVConvert JSON to CSV for spreadsheets & data imports.XML to CSVConvert XML to CSV for spreadsheets & data imports.TOML to CSVConvert TOML to CSV for spreadsheets & data imports.YAML to CSVConvert YAML to CSV for spreadsheets & data imports.JSON to YAMLConvert JSON to YAML for Kubernetes, Ansible & CI.XML to YAMLConvert XML to YAML for config & pipelines.TOML to YAMLConvert TOML to YAML for config & pipelines.JSON to TOMLConvert JSON to TOML config.XML to TOMLConvert XML to TOML config.YAML to TOMLConvert YAML to TOML config.JSON to JavaGenerate Java classes from JSON.XML to JavaGenerate Java classes from XML.TOML to JavaGenerate Java classes from TOML.YAML to JavaGenerate Java classes from YAML.JSON to GoGenerate Go structs from JSON.XML to GoGenerate Go structs from XML.TOML to GoGenerate Go structs from TOML.YAML to GoGenerate Go structs from YAML.JSON to SchemaGenerate a JSON Schema from JSON.XML to SchemaGenerate a JSON Schema from XML.TOML to SchemaGenerate a JSON Schema from TOML.YAML to SchemaGenerate a JSON Schema from YAML.JSON to ProtobufGenerate Protocol Buffers messages from JSON.XML to ProtobufGenerate Protocol Buffers messages from XML.TOML to ProtobufGenerate Protocol Buffers messages from TOML.YAML to ProtobufGenerate Protocol Buffers messages from YAML.JSON to TypeScriptGenerate typed TypeScript interfaces from JSON.XML to TypeScriptGenerate typed TypeScript interfaces from XML.TOML to TypeScriptGenerate typed TypeScript interfaces from TOML.YAML to TypeScriptGenerate typed TypeScript interfaces from YAML.JSON to PydanticGenerate Pydantic BaseModel classes from JSON.XML to PydanticGenerate Pydantic BaseModel classes from XML.TOML to PydanticGenerate Pydantic BaseModel classes from TOML.YAML to PydanticGenerate Pydantic BaseModel classes from YAML.JSON to KotlinGenerate Kotlin data classes from JSON.XML to KotlinGenerate Kotlin data classes from XML.TOML to KotlinGenerate Kotlin data classes from TOML.YAML to KotlinGenerate Kotlin data classes from YAML.JSON to RustGenerate serde-ready Rust structs from JSON.XML to RustGenerate serde-ready Rust structs from XML.TOML to RustGenerate serde-ready Rust structs from TOML.YAML to RustGenerate serde-ready Rust structs from YAML.JSON to C#Generate C# classes from JSON.XML to C#Generate C# classes from XML.TOML to C#Generate C# classes from TOML.YAML to C#Generate C# classes from YAML.JSON to PythonGenerate Python dataclasses from JSON.XML to PythonGenerate Python dataclasses from XML.TOML to PythonGenerate Python dataclasses from TOML.YAML to PythonGenerate Python dataclasses from YAML.JSON to RubyGenerate Ruby structs from JSON.XML to RubyGenerate Ruby structs from XML.TOML to RubyGenerate Ruby structs from TOML.YAML to RubyGenerate Ruby structs from YAML.JSON to SwiftGenerate Swift Codable structs from JSON.XML to SwiftGenerate Swift Codable structs from XML.TOML to SwiftGenerate Swift Codable structs from TOML.YAML to SwiftGenerate Swift Codable structs from YAML.JSON to DartGenerate null-safe Dart classes from JSON.XML to DartGenerate null-safe Dart classes from XML.TOML to DartGenerate null-safe Dart classes from TOML.YAML to DartGenerate null-safe Dart classes from YAML.JSON to C++Generate C++ structs from JSON.XML to C++Generate C++ structs from XML.TOML to C++Generate C++ structs from TOML.YAML to C++Generate C++ structs from YAML.Excel to JSONConvert an .xlsx, .xls or .csv spreadsheet into JSON, with multi-sheet support. 100% private.JSON to ExcelTurn a JSON array of objects into a downloadable .xlsx Excel file, with multi-sheet support.XML to ExcelTurn XML with repeated elements into a downloadable .xlsx Excel file. 100% private.TOML to ExcelTurn a TOML array-of-tables into a downloadable .xlsx Excel file. 100% private.YAML to ExcelTurn a YAML list of records into a downloadable .xlsx Excel file. 100% private.SCSS to CSSCompile SCSS to CSS with Dart Sass in your browser.Sass to CSSCompile the indented Sass syntax to CSS.RSS to JSONConvert RSS 2.0 / Atom feeds to structured JSON.Markdown to HTMLRender Markdown to clean HTML — tables, code, links.HTML to MarkdownConvert HTML into clean Markdown with Turndown.Image to Base64Encode an image to a Base64 data URI and CSS background.Base64 to ImageDecode Base64 or a data URI back to an image.SVG to PNGRasterize SVG to PNG at any size, transparent or solid background. 100% private.SVG to JPGConvert SVG to a compact JPEG with adjustable quality and background fill. 100% private.SVG to WebPConvert SVG to a small, modern WebP with transparency and quality control. 100% private.JSON to Base64Encode JSON to UTF-8-safe Base64 for data URIs & tokens.Base64 to JSONDecode Base64 back to JSON and pretty-print it.XML to Base64Encode XML to Base64 for SOAP, SAML & transport.Base64 to XMLDecode Base64 to XML and check well-formedness.YAML to Base64Encode YAML to Base64 for Kubernetes Secrets.Base64 to YAMLDecode Base64 / K8s Secret values back to YAML.

Code Editors

Run & edit code in 16 languages right in your browser

Universal Code EditorMulti-language code editor with 25+ languages. Switch between Python, Java, C#, JavaScript, and more with autocomplete support.TypeScript EditorOnline TypeScript editor with LIVE EXECUTION. Run TypeScript code in browser instantly with type safety and IntelliSense.JavaScript EditorOnline JavaScript editor with LIVE EXECUTION. Run JS in your browser instantly with console output, ES6+ support and autocomplete.Python EditorOnline Python editor with LIVE EXECUTION powered by Pyodide. Run Python code in browser with NumPy support.HTML/CSS EditorOnline HTML/CSS editor with LIVE PREVIEW. See your webpage changes instantly in real-time iframe preview.Java EditorOnline Java code editor with autocomplete. Write Java classes and methods with intelligent code completion and syntax highlighting.C# EditorOnline C# code editor with IntelliSense. Write .NET code with autocomplete support for classes, properties, and LINQ patterns.C++ EditorOnline C++ code editor with autocomplete. Write modern C++ code with STL support and intelligent syntax highlighting.Node.js EditorOnline Node.js/JavaScript editor with autocomplete. Write Express routes, async functions, and promises with intelligent suggestions.Go EditorOnline Go (Golang) editor with autocomplete. Write Go code with intelligent suggestions for functions, structs, and interfaces.PHP EditorOnline PHP code editor with autocomplete. Perfect for WordPress and Laravel development with intelligent code suggestions.Ruby EditorOnline Ruby code editor with autocomplete. Write Ruby on Rails code with elegant syntax and intelligent suggestions.Rust EditorOnline Rust code editor with autocomplete. Write memory-safe Rust code with ownership patterns and intelligent suggestions.Kotlin EditorOnline Kotlin code editor with autocomplete. Perfect for Android development with data classes and intelligent suggestions.R EditorOnline R code editor with autocomplete. Write data science and statistical code with ggplot2 support and intelligent suggestions.SQL EditorRun real SQLite in your browser — create tables, query with JOINs & window functions, results as tables. Persists across reloads.

Format · Validate · View

Beautify, minify, validate & explore JSON, XML, CSS, JS, HTML, SQL & YAML

JSON ViewerExplore JSON as an interactive collapsible tree — expand/collapse & copy on hover.XML ViewerExplore XML as a collapsible tree of elements, attributes & text.TOML ViewerExplore TOML as a collapsible tree of tables, arrays & values.YAML ViewerExplore YAML as a collapsible tree of keys, lists & values.CSV ViewerExplore CSV as an interactive tree — rows, columns & typed cells. Search, expand/collapse all, copy on hover.JSON FormatterFormat, validate, beautify & minify JSON, and convert it to XML, YAML, CSV, TOML & more.XML FormatterBeautify and indent messy or minified XML in your browser.XML MinifierCompress XML by stripping insignificant whitespace.JSON Schema ValidatorValidate JSON data against a JSON Schema with path-pinpointed errors (Ajv).Markdown ViewerA real-time preview tool for Markdown. Edit your Markdown content and instantly see the rendered output with support for all Markdown elements.JSONPath TesterEvaluate JSONPath expressions against your JSON — wildcards, recursion, slices and filters. 100% private.XPath TesterEvaluate XPath expressions against your XML and see every matching node instantly. 100% private.CSS FormatterBeautify and indent messy or minified CSS instantly in your browser.CSS MinifierCompress CSS by stripping comments and whitespace to speed up page loads.JavaScript FormatterBeautify and indent messy or minified JavaScript in your browser.JavaScript MinifierCompress and mangle JavaScript with terser to shrink file size.HTML FormatterBeautify and indent messy or minified HTML markup in your browser.HTML MinifierSafely compress HTML by removing comments and inter-tag whitespace.SQL FormatterPretty-print and indent SQL queries with uppercased keywords.YAML FormatterBeautify, re-indent and validate YAML in your browser.YAML ValidatorCheck YAML syntax and preview the parsed structure.XML ValidatorCheck XML is well-formed and see the exact parse error.HTML ValidatorCheck HTML markup is well-formed with balanced tags.JSON5 FormatterBeautify JSON5 or convert it to standard JSON.JSON5 ValidatorValidate JSON5 — comments, trailing commas, unquoted keys.

Text, Generators & Security

Transform & encode text, escape strings, generate passwords, hashes, QR codes & tokens

UUID GeneratorGenerate v4 (and more) UUIDs for keys, records and tests.JWT DecoderDecode and inspect a JSON Web Token's header, payload and claims.Regex TesterTest regular expressions against sample text with live matches.Speech to TextTranscribe speech to text in your browser via the Web Speech API.Case ConverterConvert text between uppercase, lowercase, title case, camelCase, snake_case, kebab-case, and more. Perfect for developers and writers.Text ReverserReverse text, words, or characters in multiple ways. Create mirror text, word puzzles, or backwards text effects.Lorem Ipsum GeneratorGenerate placeholder text for design mockups and development projects. Choose paragraphs, sentences, or words.Text to SpeechConvert text to spoken audio using browser-based TTS. Multiple voices, adjustable speed and pitch. Perfect for accessibility.Base64 Encoder/DecoderEncode and decode Base64 strings. Essential for API development, data transmission, and embedding images in HTML/CSS.URL Encoder/DecoderEncode and decode URLs and query parameters. Make URLs safe for transmission and handle special characters properly.HTML Entity EncoderConvert HTML special characters to entities and vice versa. Prevent XSS attacks and display code snippets safely.Hash GeneratorGenerate MD5, SHA-1, SHA-256, and SHA-512 hashes from text. Perfect for checksums, password hashing, and data integrity.Diff CheckerA powerful tool to compare text or code side by side. Easily identify changes between two versions of text files or documents.Word CountA simple tool to count the number of words in your text. Great for writers, students, and professionals who need to track their word usage.Character CountQuickly count the characters in your text, including spaces. Perfect for meeting character limits in social media posts, SMS, or web forms.Password GeneratorCreate strong, random, secure passwords with custom length and character sets. 100% client-side.QR Code GeneratorTurn any URL or text into a QR code and download it as PNG or SVG. Live preview, 100% private.HMAC GeneratorCompute HMAC-SHA256, SHA-384, SHA-512 and SHA-1 from a message and secret key, as hex or Base64. 100% private.JWT EncoderBuild and sign a JSON Web Token (HS256/384/512) from your payload and secret, right in your browser.Meta Tag GeneratorGenerate SEO, Open Graph and Twitter Card meta tags from a simple form and copy the HTML.Favicon GeneratorTurn an image, letter or emoji into a multi-size favicon.ico and PNG icon set with the <head> HTML. 100% private.String EscaperEscape/unescape strings for JSON, JS, CSV, SQL, HTML.JSON EscapeEscape/unescape JSON strings per RFC 8259.JavaScript EscapeEscape/unescape JS string & template literals.SQL EscapeEscape single quotes for SQL string literals.HTML EscapeEscape/unescape HTML entities to prevent XSS.XML EscapeEscape/unescape the five XML predefined entities.CSV EscapeQuote/escape CSV fields per RFC 4180.Slug GeneratorTurn a title into a clean, URL-safe slug.Bcrypt GeneratorHash and verify passwords with bcrypt in your browser.

Network & Utilities

Subnets, IP/CIDR, MAC, user-agent & email tools, HTTP codes, calculators & references

Number Base ConverterConvert numbers between binary, octal, decimal and hex.Cron ExpressionTranslate cron schedules to English and see next runs.REM to PXConvert CSS rem and px units with any root font size.URL ParserBreak a URL into protocol, host, path, query and hash.Number to WordsSpell out any number in English — cheques and forms.Subnet CalculatorIPv4 CIDR to network, mask, host range and counts.Roman NumeralsConvert numbers ↔ Roman numerals (1–3999), both ways.Credit Card ValidatorLuhn-check a card number and detect the brand.Punycode ConverterConvert IDN domains to/from ASCII Punycode.User-Agent ParserBreak a UA string into browser, OS, device and CPU.HTTP Status CodesFull reference of HTTP status codes 100–511.CIDR to IP RangeConvert an IPv4/IPv6 CIDR block to its first & last IP and address count.IP Address ConverterConvert an IPv4 address to/from decimal, hex, binary and octal.IPv6 Expand & CompressExpand an IPv6 address to full form or compress it per RFC 5952.MAC Address LookupIdentify the vendor (OUI) of a MAC address and normalize its format.MAC Address GeneratorGenerate random MAC addresses with custom OUI, bits and format.Email Header AnalyzerTrace email delivery hops and read SPF/DKIM/DMARC from raw headers.

Time & Calendar

Time-zone converters, world clock & calendar tools

Private by design

Free developer tools that keep your data on your device

Seagit Tools is a collection of 241+ free utilities developers reach for every day — formatting and validating JSON, YAML and XML, converting between data formats, generating typed models, encoding Base64 and JWTs, hashing, and converting time zones. Instead of hunting for a different single-purpose site each time, they live in one fast place with a consistent interface.

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100% client-side

Every tool runs in your browser. When you paste JSON, write code or convert a file, the work happens locally in JavaScript (and a WebAssembly Web Worker for the code editors) — nothing you enter is ever uploaded to a server.

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Instant, no signup

Results appear as you type. No account to create, no upload limits, and no waiting on a server round-trip — and the tools keep working on flaky connections once the page has loaded.

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Safer for real work

Developers routinely paste configuration, tokens and production payloads into online tools. Because everything is processed client-side, sensitive data never leaves your machine — a safer default than tools that send your input to a backend.

Who builds Seagit Tools & how privacy works →