Dev Tools

Generate ASCII diagrams, flowcharts, wireframes, tables, and trees in plain text. Perfect for README files, code comments, AI prompts, and documentation.

Build simple webpage wireframes by dragging and dropping layout blocks onto a canvas. Export as PNG or HTML skeleton.

Upload and explore SQLite database files in your browser. Browse tables, view data, and run SQL queries — no server needed.

Format and beautify SQL queries online. Supports MySQL, PostgreSQL, SQLite, T-SQL, PL/SQL and more with dialect-aware formatting.

Paste a SQL query and get a clear, step-by-step explanation in plain English. Works with SELECT, JOIN, WHERE, GROUP BY, CTEs, UPDATE, INSERT, and DELETE — all client-side.

View and inspect JSON Lines (JSONL / NDJSON) files online. Paste or upload a file and browse each record pretty-printed, with per-line validation, search and table view — all client-side.

View and explore JSON as a collapsible, color-coded tree. Paste or upload JSON, expand/collapse nodes, search keys and values, copy JSON paths, and format or minify — all client-side.

Convert text between Unix (LF), Windows (CRLF), and Classic Mac (CR) line endings. Detect mixed endings, view counts, trim trailing whitespace, and copy or download the result — all client-side.

Lint Dockerfiles online with 20+ Hadolint-style rules. Catch :latest tags, deprecated MAINTAINER, ADD vs COPY, apt-get pitfalls, missing USER/HEALTHCHECK and more — all in your browser.

Optimize boolean expressions online - apply De Morgan's laws, remove double negations, and simplify logic for PHP, JavaScript, and Python.

Create iCalendar events online - generate .ics files for Google Calendar, Outlook integration and event management.

Real-time LaTeX editor with live preview - write LaTeX on left, see rendered output on right with equation support and templates.

Real-time Markdown editor with live preview - write on left, see HTML output on right for seamless editing.

Live Markdown viewer with side-by-side preview - paste GFM Markdown on the left, see syntax-highlighted HTML rendered on the right. 100% client-side.

Generate a linked Table of Contents from your Markdown headings instantly.

Validate Markdown syntax and catch common errors like unclosed code fences, broken links, missing alt text, and bad heading formatting.

Extract every link from a Markdown document — inline, reference, autolink, image, and bare URLs. Filter, dedupe, and export to CSV, JSON, or plain text.

Extract HTML select options online - perfect for web development and form data analysis tasks.

Extract checkboxes from HTML input elements online - convert form data to multiple formats for development and analysis.

Extract radio buttons from HTML input elements online - parse form data and convert to multiple formats for development.

Extract URLs from HTML content online - parse anchor links and convert to multiple output formats.

Convert time between zones and formats online - handle global timestamps and scheduling with ease.

Calculate dates and time durations online - add/subtract time periods and sum multiple durations easily.

Calculate date differences online - find exact time between dates in days, weeks, months, and years.

Two-way PHP date formatter. Build and preview date() / DateTime::format() output live, or paste an example date and detect the matching PHP format string. Full format-character reference included.

Two-way Python date formatter. Build and preview datetime.strftime() output live, or paste an example date and detect the matching strptime format string. Full directive reference included.

Two-way C# / .NET date formatter. Build and preview DateTime.ToString() output live, or paste an example date and detect the matching format string for ParseExact. Custom and standard specifier reference included.

Two-way Java date formatter. Build and preview LocalDateTime.format() output live, or paste an example date and detect the matching DateTimeFormatter.ofPattern() string. Full pattern-letter reference included.

Convert Unix timestamps to human-readable dates and dates to epoch time. Supports seconds, milliseconds, UTC, and local timezone.

Test JavaScript code online - run snippets, debug errors, and compare performance in browser environment.

Save, organise, search and copy code snippets in your browser. Supports categories, tags, JSON export/import — no account needed.

Split Markdown files into chunks by header level. Inspired by LangChain MarkdownHeaderTextSplitter — perfect for RAG pipelines and vector databases.

Test regular expressions online - validate patterns with real-time matching and detailed results display.

Test regex find-and-replace patterns online — live preview, match highlighting, backreferences ($1, $&), and full flag support.

Browse 100+ common regex patterns with live tester, one-click copy, and plain-English explanations. Searchable by category.

Paste a regex and get a token-by-token explanation in plain English. Supports anchors, groups, lookarounds, named captures, and live match testing.

Validate and parse TOML files online. Instantly check for syntax errors with line and column number details.

Validate and format YAML online. Instantly detect syntax errors with line and column numbers.

Validate JSON against schemas online - generate schemas from examples, support for draft-07, draft-2019-09, draft-2020-12 with detailed error reports.

Transform or split JSON arrays with field selection, renaming, and removal - 1-to-1 transformation and 1-to-2 splitting with bulk processing and easy reset.

Merge multiple JSON files into one with concatenation, deduplication, and key-based merging strategies. Supports bulk processing and preserves data structure for seamless consolidation.

Flatten nested JSON structures to flat key-value pairs - customize delimiters, control depth, and choose array handling methods for seamless data transformation.

Compare two JSON objects and highlight differences — added, removed, and changed keys shown side by side.

Diff two JSON documents and emit a minimal RFC 6902 patch (add, remove, replace, copy, move, test). Verifies the patch by re-applying it to the source — 100% client-side.

Diff two JSON documents and emit a minimal RFC 7396 merge patch. Null deletes keys, objects deep-merge — simpler than RFC 6902. Apply-back verification, 100% client-side.

Compare two OpenAPI / Swagger specs (JSON or YAML) and instantly see breaking, non-breaking, and informational changes — endpoints, parameters, responses, and schemas. 100% client-side.

Compare two HTTP header blocks online and highlight added, removed, and changed headers with malformed-line detection.

Compare two CSV files and highlight differences — added, removed, and modified rows with cell-level change highlighting.

Format and beautify JSON with customizable indentation styles - support for 4 space, 3 space, 2 space, tab, and compact formats. Validate against multiple JSON specifications with error fixing.

Format GraphQL variables online. Paste a variables object or full GraphQL request body, auto-extract variables, validate JSON, sort keys, and wrap back into request payloads.

Format and beautify GraphQL queries, mutations, subscriptions, and fragments online. Pretty-print with 2/4-space or tab indentation, or minify to a single line — 100% client-side.

Sort JSON object keys alphabetically (A-Z or Z-A) with recursive or top-level depth, optional array sorting, case sensitivity, and four indent styles. Produces canonical, diff-friendly JSON entirely in your browser.

Validate existing UUIDs with format analysis (v1, v4, v5) - check UUID structure, extract metadata, and analyze timestamp, MAC address, and hash information.

Generate Tailwind CSS button styles online - create custom buttons with utility classes and live preview.

Compare text differences online - highlight changes between documents with side-by-side diff viewer.

Convert text to array format online - transform lines into programming arrays for development tasks.

Convert text case online - transform between camelCase, snake_case, PascalCase, and other programming styles.

Clean messy text online - remove unwanted formatting while preserving structure for better readability.

Remove duplicate items from text online - works with line-separated, space-separated, JSON arrays, and CSV formats.

Find mismatched brackets and quotes online - debug code syntax errors and validate parentheses pairs.

Sort text alphabetically online - organize lists, CSV, arrays, and JSON data in ascending or descending order.

Count sentences, words, characters, paragraphs, and estimate reading time online - comprehensive text analysis tool for writers and editors.

Map two columns of data into array notation or JSON object format. Perfect for creating mappings from tabular data.

Find duplicate lines in text online - identify repeated entries with unique and total duplicate counts for data analysis and text processing.

Test and evaluate JSONPath expressions against JSON data instantly in your browser.

Test jq filter expressions against JSON in your browser. Pipe, select, map, sort_by, group_by, and more — entirely client-side with sample queries and inline errors.

Preview any website across mobile, tablet, and desktop viewports instantly. Test responsive layouts on iPhone, iPad, and desktop screen sizes without leaving your browser.

Obfuscate JavaScript code online to protect it from reverse engineering. Supports variable renaming, string encryption, control flow flattening, and dead code injection.

Escape special characters in JSON strings or unescape encoded JSON back to readable format.

Validate semantic version ranges online. Check if a semver version satisfies npm-compatible ranges like ^1.0.0, ~1.2.3, >=1.0.0 <2.0.0 and more. Supports batch validation.

Compare and sort semantic versions online. Determine which version is older or newer, sort lists of versions, and inspect parsed major/minor/patch/prerelease/build components per SemVer 2.0.0.

Parse HTTP Cookie and Set-Cookie headers online. Break down cookie strings into name, value, and attributes. View security flags like HttpOnly, Secure, SameSite, expiry and path in a clean table.

Generate and verify webhook signatures online. Test Stripe-style signing headers, generic HMAC signatures, SHA1/SHA256/SHA512 algorithms, and multiple signature encodings in your browser.

Build sample webhook JSON bodies online with nested fields, arrays, timestamps, and copy-ready request headers for Stripe-style or custom integrations.

Calculate Linux/Unix file permissions online. Set owner, group, and others permissions with checkboxes and get the octal value, symbolic notation, and chmod command instantly.

Parse raw .env files into structured JSON, detect duplicate keys, flag syntax issues, and export clean environment variable lists online.

Compare two .env files online, highlight added, removed, and changed variables, and catch duplicate or invalid lines before deployment.

Evaluate Content Security Policy headers online, detect risky directives like unsafe-inline or wildcards, and review hardening recommendations.

Analyze how often each word appears in your text. Sort by frequency, alphabetically, or by word length. Filter stop words and minimum count, then export results as CSV.

Inspect Unicode characters in text. View code points, UTF-8/UTF-16 bytes, character names, categories, and HTML entities for any character.

Normalize Unicode text to NFC, NFD, NFKC, or NFKD online. Compare side-by-side outputs, byte counts, and per-character decomposition. Reveal hidden combining marks and ligatures.

Paste a saved webhook request and instantly get cURL, fetch, or Axios code to replay it. Debug failed webhook deliveries, test local handlers, and reproduce webhook events without waiting for a retry.

Parse raw HTTP requests online. Instantly break down method, URL, path, query parameters, headers, and body into structured tables. Supports all HTTP methods and JSON body formatting.

Validate robots.txt files online. Parse User-agent groups, detect syntax errors, check Allow/Disallow rules, test URLs against crawl rules, and preview Sitemap directives instantly in your browser.

Analyze HAR (HTTP Archive) files online. Inspect every network request with status, size, timing, headers, and response body — exported from Chrome, Firefox, or Safari DevTools. 100% client-side.

Test and evaluate XPath expressions against XML or HTML documents instantly in your browser. Supports XPath 1.0 with axes, predicates, and node-set functions — 100% client-side.

Parse curl commands and inspect every part of the HTTP request — method, URL, query parameters, headers, body, basic auth, cookies, and flags — broken down into a clean structured view. 100% client-side.

Pick an open source license (MIT, Apache 2.0, BSD 2/3-Clause, GPL-3.0, AGPL-3.0, MPL 2.0, ISC, Unlicense), fill in your year and name, and generate a ready-to-save LICENSE file. Includes a quick feature-comparison table.