Guides & How-Tos
Why Passport and Visa Photo Apps Reject Your File
An exact-size photo still comes back rejected. Here are the automated checks a portal runs first, and how to measure them yourself in a browser tab.
Guides & How-Tos
Step-by-step walkthroughs you can follow along in the browser, with CapyToolkit tools on hand to verify each result.
Guides & How-Tos
Prepare a USCIS Filing Packet as Clean PDFs Without Uploading a Single Page
Assemble a USCIS filing packet with current form editions, clean scans, ordered merges, and portal-ready file sizes, all without uploading a page.
Guides & How-Tos
After IndexNow: 6 Launch Channels Indie Founders Skip, and How to Hit Them in a Weekend
IndexNow pings every URL, then launch week goes silent. Here are six distribution channels solo founders skip, with weekend time budgets for each.
Guides & How-Tos
Wide-Gamut Display Color Management for Web Designers: Converting Display P3 and Adobe RGB to sRGB in the Browser
How wide-gamut displays create colors sRGB cannot represent, how browsers handle the mismatch, and how to verify colors stay in gamut before production.
Guides & How-Tos
Home Network Diagnostics for Video Calls and Gaming: NAT, Jitter, and Packet Loss
Diagnose home network quality for video calls and gaming with NAT type detection, jitter measurement, and packet loss tracking in your browser.
Guides & How-Tos
When Your Video Call Freezes, the Problem Is Not What You Think
A frozen video call usually means something on the P2P path is misconfigured, not the app itself. Learn to diagnose your network and find the real cause.
Guides & How-Tos
Building Accessible, Contrast-Safe Color Systems in CSS Using OKLCH and WCAG
Learn to build a complete, contrast-safe color system in the browser with OKLCH and WCAG 2.1, from base color to CSS and Tailwind v4 tokens.
Guides & How-Tos
Letterboxing and Aspect Ratio Math for Video and Photo Crops
Predict letterbox and pillarbox bar sizes before export, choose the right delivery ratio per platform, and verify dimensions with a client-side calculator.
Guides & How-Tos
Build CSS Gradients Visually Without Sending Design Data to a Server
Build linear, radial, and conic CSS gradients in your browser. Learn color stop control, OKLCH interpolation, angle coordinates, and multi-format output.
Guides & How-Tos
Network Diagnostics Without Cloud APIs: Subnet Planning, P2P Testing, and URL Inspection
Use browser tools to plan subnets, test P2P latency, and inspect URLs for tracking tokens. No uploads, no cloud, no sign-up.
Install from Microsoft Store