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All 95 Developer Tools

Every tool on CodersUtility, grouped by category. Almost all of them run entirely in your browser — nothing you paste is uploaded to a server. The few that need the network say so on their own page.

JSON21

JSON Schema BuilderBuild JSON Schema for LLM structured outputs and export to OpenAI, Anthropic, Gemini, Zod, and Pydantic

JSON Payload GeneratorBuild a JSON request body by adding keys with a datatype and sample value, including nested objects and arrays

JSON FormatterBeautify and format raw JSON with syntax highlighting

JSON ValidatorValidate JSON syntax and get clear error messages

JSON ViewerExplore JSON as an interactive collapsible tree

JSON Tree ViewerVisual tree diagram with connector lines for JSON exploration

JSON to TableRender JSON as a clean Key / Value table with expandable nested rows

JSON MinifierStrip whitespace to compress JSON for production

JSON DiffCompare two JSON objects with change highlights

JSON to CSVFlatten JSON arrays into downloadable CSV format

JSON to XMLConvert JSON structure to equivalent XML markup

JSONPath TesterRun JSONPath expressions against a JSON payload live

JSON Schema ValidatorValidate a JSON payload against a JSON Schema

JSON Escape / UnescapeUnescape stringified JSON or escape JSON to a string

CSV to JSONConvert CSV or TSV data into a clean JSON array of objects

JSON ⇄ YAML ConverterConvert between JSON and YAML in either direction

JSON to TypeScriptGenerate TypeScript interfaces and types from a JSON sample

JSON to GoGenerate Go structs with JSON tags from a JSON sample

JSON to JavaGenerate Java POJO classes from a JSON sample

JSON to C#Generate C# classes or records from a JSON sample

XML to JSONConvert XML markup into equivalent, readable JSON

Encoding4

Base64 Encode / DecodeEncode text or files to Base64 and decode back

URL Encode / DecodePercent-encode and decode URLs and query parameters

JWT DecoderDecode and inspect JWT header, payload, and signature

HTML Entity Encode / DecodeEncode special characters to HTML entities and back

Code6

Compare Files / Diff CheckerCompare two files or blocks of text and see every added, removed, and changed line

Code PlaygroundWrite HTML, CSS, and JavaScript in a VS Code editor and run it live in your browser

HTML BeautifierFormat and indent messy HTML markup instantly

JS Beautifier / MinifierBeautify or minify JavaScript code in one click

Regex TesterTest regular expressions with live match highlighting

Markdown PreviewWrite Markdown and preview the rendered output live

Text7

Compare Files / Diff CheckerCompare two files or blocks of text and see every added, removed, and changed line

Case ConverterConvert text between camelCase, snake_case, PascalCase, and more

Word & Character CounterCount words, characters, sentences, and reading time

Password GeneratorGenerate strong, random passwords with custom rules

Remove Duplicate LinesRemove duplicate lines from text with sorting and trim options

Lorem Ipsum GeneratorGenerate classic Lorem Ipsum placeholder text in any length

PDF to Markdown ConverterConvert a PDF into clean Markdown in your browser, with headings, lists and links detected

Other Converters

Image9

Image ConverterConvert images between PNG, JPG, WebP, SVG, HEIC and more

Image ResizerResize images and make thumbnails at any size

Background RemoverRemove the background from a photo of a person, without uploading anything

HEIC to JPG converterConvert iPhone HEIC photos to JPG in your browser

Image compressorCompress JPG, PNG and WebP images privately

SVG to PNG converterRasterize SVG to PNG at any scale

PNG to JPG converterConvert PNG images to JPG, in batch

JPG to PNG converterConvert JPG images to PNG, in batch

WebP to PNG converterConvert WebP images to PNG, in batch

Number3

Number Base ConverterConvert numbers between binary, octal, decimal, and hex

UNIX Timestamp ConverterConvert UNIX timestamps to human-readable dates and back

UUID GeneratorGenerate UUID v4 identifiers in bulk, instantly

Web / API8

REST API TesterSend GET, POST, PUT, and DELETE requests with headers and body

cURL Command BuilderBuild a cURL command from a form with copy-to-clipboard

API Response FormatterAuto-detect and pretty-print JSON or XML API responses

GraphQL FormatterFormat and validate GraphQL queries with clean indentation

Mock Data GeneratorGenerate realistic fake user, product, and address JSON

HTTP Header AnalyzerParse raw HTTP headers into a readable, annotated table

Query String ParserParse and inspect URL query parameters visually

HTTP Status CodesReference guide for all HTTP status codes with explanations

Security7

Hash GeneratorGenerate MD5, SHA-1, SHA-256, and SHA-512 hashes

Password Strength CheckerAnalyze password entropy and strength with improvement tips

HMAC GeneratorGenerate HMAC-SHA256 authentication signatures

RSA Key GeneratorGenerate RSA public/private key pairs fully in-browser

SSL Certificate DecoderPaste a PEM certificate and parse all fields and validity dates

JWT BuilderBuild and sign JWT tokens with a custom payload in-browser

CORS Request TesterTest CORS preflight from browser to any public endpoint

Development13

SQL Schema DiffCompare two SQL table schemas and generate ALTER statements to sync either side

QR Code GeneratorGenerate QR codes from any URL or text with download

.gitignore GeneratorPick your tech stack and build a .gitignore instantly

README GeneratorFill a form and generate a polished GitHub README.md

Environment Var FormatterConvert between .env files, JSON, and a table view

Epoch / Date ConverterEpoch conversion, timezones, and a duration calculator

Dockerfile HelperReference and snippet generator for Dockerfile patterns

Barcode GeneratorGenerate Code128, EAN, UPC, and Code39 barcodes

IP Address InfoLook up geolocation and ISP for any public IP

DNS Lookup ToolQuery A, AAAA, CNAME, MX, TXT, and NS records

Email ValidatorCheck email address syntax in bulk and flag disposable, role, and typo domains

Cron Expression GeneratorBuild and explain cron schedules, with a plain-English reading and the next run times

IPv4 Subnet CalculatorCompute network, broadcast, host range, and masks from any CIDR block

Frontend / CSS16

Code PlaygroundWrite HTML, CSS, and JavaScript in a VS Code editor and run it live in your browser

CSS Gradient GeneratorVisual gradient builder with linear, radial, and conic CSS output

Box Shadow GeneratorInteractive box-shadow builder with live preview and layering

Border Radius GeneratorVisual border-radius editor with per-corner and elliptical control

Flexbox PlaygroundInteractive Flexbox visualizer to explore every flex property

CSS Grid GeneratorBuild CSS Grid layouts visually and copy the code

SVG OptimizerClient-side SVG minification that removes metadata and cleans markup

Image to Base64Convert any image file to a Base64 data URI for embedding

Favicon GeneratorGenerate favicon.ico and all PNG sizes from an uploaded image

RGB to HEX converterConvert RGB color values to hexadecimal

RGBA to HEX converterConvert RGBA values to hex, alpha included

HEX to RGB converterConvert hexadecimal colors to RGB

HEX to OKLCH converterConvert hex codes to the OKLCH color space

Color pickerPick a color and copy HEX, RGB, HSL or OKLCH

Color contrast checkerCheck WCAG contrast ratios between two colors

Meta Tag GeneratorGenerate SEO, Open Graph and Twitter Card meta tags with live previews

Other Converters4

Markdown ⇄ HTML ConverterConvert Markdown to HTML and HTML back to Markdown, with live preview

Other Converters

TOML to JSONConvert TOML config into JSON and back, in either direction

Other Converters

YAML to GoGenerate Go structs with tags from a YAML document

Other Converters

PDF to Markdown ConverterConvert a PDF into clean Markdown in your browser, with headings, lists and links detected

Other Converters