Tutorials, deep-dives, and privacy-first thinking about developer tools.
Showing 13–24 of 61 posts
JWT exp, nbf, and iat are Unix timestamps in seconds. Learn to read them in 3 seconds, convert them to a date, and check token expiry by hand.
The Year 2038 problem overflows 32-bit Unix time on 19 Jan 2038. Here's who is still affected in 2026 and how to test your own systems for it.
PNG, JPG, WebP, or AVIF? A 2026 guide comparing transparency, compression, browser support, and file size so you pick the right image format every time.
Learn what the JWT exp, nbf, and iat claims mean, how to read token expiry without doing epoch math by hand, and the clock-skew gotchas that bite in 2026.
Your JavaScript timestamp is in milliseconds while most backends use seconds, so it looks 1000× too big. Here is why, and how to convert it safely.
Unix timestamps come in seconds, milliseconds, microseconds, and nanoseconds. This 2026 cheat sheet shows how to tell them apart and convert safely.
Sign a JWT in the browser with HS256 and the Web Crypto API — five lines of JavaScript, no library, no server. The 2026 walkthrough.
When an API returns 401 Unauthorized in 2026, the JWT is usually the smoking gun. Decode the token, read exp, aud, iss — and fix the bug in 90 seconds.
Converting a Unix timestamp to a date is one division operation, but the timezone you format it in is the whole bug. Here's how to get it right.
RFC 3986 names just 66 characters as unreserved — and most encoders mishandle the rest of printable ASCII. Here's what each one actually is, and why it matters.
jwt.io is the JWT inspector most developers reach for, but should production tokens leave your machine? Here's how the iKit JWT Decoder compares in 2026.
The JWT alg: none vulnerability lets attackers forge tokens without a secret. Here's how the exploit works and why libraries still trip on it in 2026.