All DevCoreTools

JSON Formatter

Format, validate, inspect, and export JSON locally.

/json-formatter

JSON Validator

Validate JSON syntax with clear messages, hints, and formatted output.

/json-validator

CSV to JSON

Parse CSV rows into structured JSON locally.

/csv-to-json

JSON Lines / NDJSON Validator

Validate JSON Lines and NDJSON locally with per-line errors, summaries, and JSON array output.

/json-lines-validator

JSON to CSV

Convert JSON arrays and objects into spreadsheet-ready CSV locally.

/json-to-csv

JSON Minifier

Validate and remove unnecessary JSON whitespace for compact output.

/json-minifier

JSON to SQL Converter

Generate SQL INSERT statements from JSON locally.

/json-to-sql

JSON to TypeScript Interface Generator

Generate TypeScript interfaces from JSON locally.

/json-to-typescript

JSON to YAML

Convert valid JSON into readable, configurable YAML locally.

/json-to-yaml

CSV to SQL Insert Generator

Generate SQL INSERT statements from CSV locally.

/csv-to-sql-insert

JSON Escape / Unescape

Escape and unescape JSON string literals locally.

/json-escape-unescape

JSON to Zod Schema Generator

Generate Zod schemas from JSON locally.

/json-to-zod

YAML to JSON

Convert YAML mappings, sequences, and configuration documents into valid JSON locally.

/yaml-to-json

JSON Diff

Compare two JSON values and inspect added, removed, changed, and type-changed data.

/json-diff

JSONPath Tester

Test JSONPath expressions and inspect matching values, paths, pointers, and metadata.

/jsonpath-tester

SQL Prettifier

Format and minify SQL locally with dialect-aware options.

/sql-prettifier

JSON Schema Validator

Validate JSON data against JSON Schema with clear paths, keywords, and error details.

/json-schema-validator

YAML Validator

Validate YAML syntax and configuration structure locally.

/yaml-validator

YAML Formatter

Format and validate YAML configuration files locally.

/yaml-formatter

/docker-compose-formatter-validator

Docker Compose Formatter / Validator

Format and validate Docker Compose YAML with service and resource checks.

XML Tools

XPath Tester

Test XPath expressions against XML and inspect matching nodes, attributes, text values, and paths.

/xpath-tester

.env Formatter / Validator

Format and validate environment variable files with duplicate and secret warnings.

/env-formatter-validator

XML Formatter

Format, beautify, validate, copy, and download XML locally.

/xml-formatter

TOML Formatter

Format and validate TOML configuration files locally.

/toml-formatter

XML to JSON Converter

Convert and validate XML as configurable, readable JSON locally.

/xml-to-json

HTML Formatter / Beautifier

Format and beautify HTML locally with indentation and structural warnings.

/html-formatter

CSS Selector Tester

Test CSS selectors against HTML and inspect matched elements, snippets, paths, and warnings.

/css-selector-tester

HTML Minifier

Minify HTML locally with conservative whitespace, comment, and template-preservation options.

/html-minifier

HTML Previewer / Live HTML Preview

Preview HTML live in an isolated browser frame with safety warnings and export actions.

/html-previewer

Markdown to HTML Converter

Convert Markdown into sanitized, reusable HTML locally with preview, copy, and download actions.

/markdown-to-html

/open-graph-meta-tag-previewer

Open Graph / Meta Tag Previewer

Preview Open Graph, Twitter Card, and SEO meta tags from pasted HTML.

robots.txt Tester

Test pasted robots.txt rules locally for crawler access decisions and warnings.

/robots-txt-tester

Sitemap XML Validator

Validate pasted sitemap XML and sitemap indexes locally with URL and field warnings.

/sitemap-xml-validator

HTML to Markdown Converter

Convert pasted HTML into readable Markdown locally.

/html-to-markdown

Image Resizer

Resize PNG, JPEG, and WebP images locally with preview and download options.

/image-resizer

JWT Decoder

Decode JWT headers, payloads, claims, and timestamps locally.

/jwt-decoder

Markdown Previewer

Preview Markdown with live rendered HTML, source output, samples, and local copy/download actions.

/markdown-previewer

Meta Tag Generator / Previewer

Generate SEO, Open Graph, and Twitter Card meta tags with live previews.

/meta-tag-generator

Image Compressor

Compress PNG, JPEG, and WebP images locally with preview and download options.

/image-compressor

JWT Verifier

Verify JWT signatures with a secret or public key and inspect claim checks locally.

/jwt-verifier

/markdown-table-generator

Markdown Table Generator / Formatter

Create, edit, format, preview, copy, and download Markdown tables locally from grid, CSV, TSV, or pasted table input.

Text Diff Checker

Compare plain-text blocks and highlight line-level and word-level changes locally.

/text-diff-checker

Image Format Converter

Convert PNG, JPEG, WebP, GIF, and SVG images locally with preview and download.

/image-format-converter

EXIF Viewer / Remover

View and remove image EXIF metadata locally with privacy warnings and download.

/exif-viewer-remover

Favicon Generator

Generate favicon PNG files, app icons, manifest icons, and HTML tags locally.

/favicon-generator

String Case Converter

Convert text between common programming and writing case styles locally.

/string-case-converter

Word & Character Counter

Analyze words, characters, lines, paragraphs, bytes, and reading time locally.

/word-character-counter

Line Tools

Split, trim, sort, deduplicate, decorate, and convert line endings for plain text.

/line-tools

Color Picker / Color Converter

Pick colors and convert HEX, RGB, HSL, HSV, and CSS color formats locally.

/color-picker

JavaScript Formatter

Format and beautify JavaScript locally with syntax validation and configurable style options.

/javascript-formatter

JWK / JWKS Inspector

Inspect JSON Web Keys and JWKS key sets locally.

/jwk-jwks-inspector

CSS Gradient Generator

Create linear, radial, and conic CSS gradients with editable color stops.

/css-gradient-generator

/css-box-shadow-generator

CSS Box Shadow Generator

Create layered CSS box shadows with live preview and copy-ready CSS.

Color Contrast Checker

Check text and background color contrast for accessible web interfaces.

/color-contrast-checker

CSS Formatter

Format and beautify CSS locally with syntax feedback and copy/download actions.

/css-formatter

OpenAPI / Swagger Viewer

Inspect OpenAPI and Swagger specs locally with endpoints, schemas, and warnings.

/openapi-swagger-viewer

JavaScript Minifier

Minify JavaScript locally with syntax checks, size savings, and conservative options.

/javascript-minifier

OpenAPI Validator

Validate OpenAPI and Swagger specs locally with structured errors and warnings.

/openapi-validator

SVG Optimizer / Minifier

Optimize and minify SVG locally with validation, safe options, and size savings.

/svg-optimizer

CSS Minifier

Minify CSS locally with syntax checks, size savings, and conservative options.

/css-minifier

cURL to Code Converter

Convert cURL commands into readable HTTP request code snippets locally.

/curl-to-code-converter

GraphQL Formatter

Format GraphQL queries, mutations, fragments, and schema definitions locally.

/graphql-formatter

SVG Viewer / Formatter

View, format, inspect, copy, and download SVG markup locally with safe preview.

/svg-viewer

GraphQL Query Pretty Printer / Tester

Format, validate, and inspect GraphQL operations and variables locally.

/graphql-query-tester

HTTP Headers Parser / Formatter

Parse, format, inspect, and export HTTP headers locally with structured warnings.

/http-headers-parser

User Agent Parser

Decode browser, OS, device, engine, and bot hints from user agent strings locally.

/user-agent-parser

HTTP Cookie Parser / Builder

Parse and build Cookie and Set-Cookie headers locally with secure attribute warnings.

/http-cookie-parser

HTTP Status Code Lookup

Look up HTTP response status codes locally with meanings, examples, and API notes.

/http-status-code-lookup

MIME Type Lookup

Look up MIME types and file extensions locally with Content-Type header examples.

/mime-type-lookup

UTM Link Builder

Build campaign tracking URLs with UTM parameters, custom params, copy actions, and QR preview.

/utm-link-builder

Base64 Encoder/Decoder

Encode and decode Base64 and Base64URL text in your browser.

/base64-encoder-decoder

Regex Tester

Test patterns, capture groups, flags, and multiple values locally.

/regex-tester

UUID Generator

Generate standards-compliant UUID values in useful formats and batches.

/uuid-generator

UUID Validator / Inspector

Validate UUIDs and inspect version, variant, casing, hyphen structure, and duplicates locally.

/uuid-validator

/html-entity-encoder-decoder

HTML Entity Encoder/Decoder

Encode and decode HTML entities, symbols, and special characters locally.

URL Parser / Query String Parser

Parse full URLs, relative URLs, and query strings into structured parts.

/url-parser

Query Params to JSON Converter

Convert URL query parameters into clean JSON locally.

/query-params-to-json

JSON to Query String Converter

Convert JSON objects into URL query strings locally.

/json-to-query-string

Image to Base64 Converter

Convert local image files to Base64, data URIs, HTML snippets, and CSS snippets.

/image-to-base64

/unix-timestamp-converter

Unix Timestamp Converter

Convert Unix timestamps to readable dates and dates back to epoch time.

Hash Generator

Generate text hashes and file checksums locally with common MD5 and SHA algorithms.

/hash-generator

HMAC Generator

Generate and verify keyed HMAC signatures locally with common SHA algorithms.

/hmac-generator

SSL Certificate Decoder

Decode pasted PEM or DER X.509 certificates locally.

/ssl-certificate-decoder

CSP Header Generator

Generate Content Security Policy headers with directives, warnings, and copy-ready output.

/csp-header-generator

CORS Header Explainer / Generator

Generate and explain CORS response headers locally with validation warnings.

/cors-header-generator

Password Generator

Generate secure random passwords locally with configurable length and character rules.

/password-generator

QR Code Generator

Generate QR codes locally for URLs, text, email, phone, SMS, and Wi-Fi payloads.

/qr-code-generator

Lorem Ipsum Generator

Generate placeholder text as words, sentences, paragraphs, or HTML locally.

/lorem-ipsum-generator

/cron-expression-generator

Cron Expression Generator

Build Unix, Quartz, and Spring cron schedules with visual controls and local run previews.