ArrayKit — Privacy-first developer tools

Privacy-first developer tools — an array of utilities that run entirely in your browser. Your data never leaves your device. No tracking.

JSON

• JSON Formatter — Beautify, minify and validate JSON with error locations.
• JSON Tree Viewer — Explore JSON as a collapsible, typed tree.
• JSON Viewer — Text + collapsible tree viewer with expand/collapse and node paths.
• JSON to TypeScript — Generate TypeScript interfaces from a JSON sample.
• JSON to CSV — Convert an array of flat JSON objects to CSV.
• JSON Escape / Unescape — Escape text into a JSON string or unescape a JSON string back to raw text.
• JSON to Code — Generate Go, Rust, Python, Java, Kotlin, C# and TypeScript types from JSON.

Code Formatters

• YAML ↔ JSON — Convert YAML to JSON and back.
• Markdown Preview — Render Markdown to HTML with a live preview.
• Regex Tester — Test regular expressions live with matches, groups and flags.
• CSS Color Converter — Convert between HEX, RGB and HSL with a live swatch.
• Text Diff — Compare two texts line-by-line and see additions and removals.
• MDX Converter — Render MDX as formatted text, convert HTML → MDX, and escape text to literal MDX.
• CSS / SCSS Formatter — Beautify or minify CSS/SCSS/LESS, sort properties and remove duplicates.
• JS / TS Formatter — Beautify or minify JavaScript, TypeScript and JSX/TSX with Prettier options.
• HTML Formatter — Beautify or minify HTML, format inline CSS/JS, and preview the result.
• XML Formatter — Beautify, minify and validate XML, and convert XML ↔ JSON.
• SQL Formatter — Format SQL for MySQL, PostgreSQL, SQL Server, SQLite, BigQuery and Oracle.
• GraphQL Formatter — Format or minify GraphQL queries and schemas, validate syntax and extract operations.
• Dockerfile Formatter — Format a Dockerfile and get best-practice / lint suggestions.
• MongoDB Query Formatter — Format MongoDB shell queries and aggregation pipelines.
• Contrast Checker — Check WCAG colour contrast ratio and AA/AAA pass for any two colours.
• Mermaid Diagram Renderer — Render Mermaid diagrams (flowcharts, sequence, gantt) to SVG in your browser.
• SVG Optimizer — Minify SVG — strip comments, metadata and editor cruft, and collapse whitespace.

Text

• Case Converter — Convert text between camelCase, snake_case, kebab-case, PascalCase and more.
• Lorem Ipsum Generator — Generate placeholder lorem ipsum paragraphs, sentences or words.
• Mock Data Generator — Generate fake JSON data — names, emails, UUIDs, dates and more.

Encode / Decode

• Base64 Encode / Decode — UTF-8 safe Base64 encoding and decoding.
• URL Encode / Decode — Encode and decode URL components.
• HTML Escape / Unescape — Escape and unescape HTML special characters and entities.
• Number Base Converter — Convert integers between binary, octal, decimal and hex.
• QR Code Generator — Generate a QR code from text or a URL; download as PNG or SVG.

Images

• Image Optimizer — Re-encode and shrink images (JPEG/WebP/PNG), optionally resizing.
• Image Format Converter — Convert images between PNG, JPEG and WebP entirely in your browser.
• EXIF Viewer & Remover — View and strip EXIF metadata (including GPS) from photos — nothing is uploaded.

PDF

• Image to PDF — Combine images into a single PDF (auto / portrait / landscape).
• PDF to Images — Render PDF pages to PNG or JPG images you can download.
• Merge PDFs — Combine multiple PDFs into one, with reordering.
• Split PDF — Extract pages or ranges (e.g. 1-3,5,7-9) into a new PDF.
• Rotate PDF — Rotate all pages or a selection by 90/180/270°.
• Organize PDF — Reorder, rotate and delete pages from thumbnails, then export.
• Add Page Numbers — Stamp page numbers onto a PDF (position, format, start).
• Watermark PDF — Add a diagonal text watermark to every page.
• Crop PDF — Trim margins from every page via the crop box.
• PDF to Text — Extract selectable text from a PDF as plain text or Markdown.
• Compare PDFs — Diff the extracted text of two PDFs line-by-line.
• Compress PDF — Shrink a PDF by re-rendering each page to a JPEG at a chosen quality and resolution.

Date / Time

• Unix Timestamp Converter — Convert between Unix timestamps and human dates (local + UTC).
• UUID Generator — Generate one or many random UUID v4 values.
• Cron Explainer — Explain a cron expression and preview its next run times.

Web & DevOps

• Chmod Calculator — Convert Unix file permissions between octal and symbolic (rwx).
• .gitignore Generator — Build a .gitignore from common language and tool templates.
• HTTP Status & MIME Types — Searchable reference of HTTP status codes and MIME content types.
• Open Graph Generator — Generate Open Graph & Twitter meta tags with a live social-card preview.

Network

• CIDR / Subnet Calculator — Calculate network, broadcast, host range and mask from a CIDR block.
• IPv6 ↔ IPv4 Converter — Convert between IPv4 and IPv6 (mapped/expanded/compressed) and extract embedded IPv4.

API Tools

• cURL to Fetch — Convert a curl command to a JavaScript fetch() call.
• URL Parser — Break a URL into its parts and list query parameters.

Security

• JWT Decoder — Decode JWT header & payload and inspect exp / iat (no verification).
• Hash Generator — SHA-256 / SHA-1 / SHA-384 / SHA-512 via the Web Crypto API.
• Password Generator — Generate strong, random passwords with a strength meter (crypto-secure).
• TOTP / 2FA Generator — Generate time-based one-time passwords (2FA codes) from a base32 secret.
• JWT Signer — Create and sign a JWT (HS256/384/512) from a payload and secret — Web Crypto.

Frequently asked questions

What is ArrayKit?

ArrayKit is a privacy-first collection of developer utilities — JSON, PDF, encoding, date/time, security, formatters and more — that run entirely in your browser.

What does "privacy-first" mean here?

Every tool runs client-side in your browser. The data you paste is processed on your device and is never uploaded to a server.

Do you track or store what I enter?

No. There is no analytics on your tool input, and nothing you paste is logged or stored remotely.

Does it work offline?

Yes — once loaded, the tools keep working without an internet connection.

Do I need to install anything?

No. ArrayKit runs in any modern web browser, with nothing to install.