Developer Tools — Guides & Articles

• How to Merge Excel Files and Remove Duplicates Locally

  Published 2026-08-14

  Merge Excel files into one data-only workbook locally in your browser, then remove duplicate rows with Excel's built-in tool. No uploads.

  

• Basic Linux Commands: 13 Safe Templates to Copy

  Published 2026-08-14

  Find 13 source-checked basic Linux commands for files, text, location, and disk usage. Search, replace placeholders, and copy conservative templates without…

  

• How Do I Find the Code for My Car Key in JavaScript

  Published 2026-08-14

  Need the code value for any key in JavaScript? Press a key in the JavaScript Key Code Finder to see its key, code, location, modifiers, and keyCode.

  

• Border Radius Generator Bulk: A Token-Based Workflow

  Published 2026-08-13

  Bulk build border-radius CSS for every component in your design system. Set four corners per shape, then copy the shortest correct shorthand and verify.

  

• Cron Parser Bulk: Validate Every Five-Field Expression

  Published 2026-08-13

  Run a Cron Parser bulk pass to validate classic five-field cron syntax, normalize each rule, and preview upcoming runs in local and UTC times before deployment.

  

• Cookie Converter Command Line vs Online Tools Compared

  Published 2026-08-13

  Compare command-line and online cookie converters for parsing Cookie headers to JSON, including a strict local browser tool that never sends data.

  

• Common Port Numbers: How to Identify Any Service Port

  Published 2026-08-13

  A curated table of common TCP and UDP port numbers — search by number, service, or description, filter by protocol, and copy rows for tickets.

  

• How to Share Spotify Code as a PNG Image

  Published 2026-08-13

  Render Spotify Web API and SDK snippets as a clean light or dark PNG locally. Pick a theme, font size, and padding, then download the image for docs and posts.

  

• Clipboard Viewer Online API Alternative for Developers

  Published 2026-08-12

  Browser-based clipboard viewer API alternative. Inspect text, hidden whitespace, and JSON validity locally — no upload, no integration.

  

• Chmod Calculator Cheat Sheet for Octal and rwx Notation

  Published 2026-08-12

  Chmod calculator cheat sheet mapping octal digits, rwx positions, and special bits to decode any file mode, verify setuid, setgid, and sticky states.