Blog

Tips, guides, and tutorials for our free online tools.

DeveloperOctober 25, 2026

I Weighed My Own Site in Production: 1.8 MB of JavaScript on Every Tool Page

I measured every page I ship: HTML is tiny once gzipped, but tool pages load 1.8 MB of JavaScript — including a PDF engine on the JSON formatter. Here are the real numbers and the fix.

DeveloperOctober 21, 2026

How to Read a JWT by Hand (and the Three 401s It Would Have Saved Me)

A JSON Web Token is three base64url chunks and a signature. Decoding one by eye explains most auth failures in under a minute: expiry, clock skew, wrong key, wrong audience.

DeveloperOctober 19, 2026

The Regex That Passed in the Tester and Broke in Production

Five real reasons a regular expression behaves differently in your app than in an online tester: the global-flag statefulness bug, the trailing-newline dollar, greedy quantifiers, the ASCII-only \d, and catastrophic backtracking.

DesignerOctober 18, 2026

I Converted My Own Site's Images to JPG. The Text Got Worse — Here's the Data

I ran this site's 1200×630 share cards through PNG, JPG, and WebP at several quality levels and logged every byte. The 'just compress it to JPG' advice falls apart the moment the image contains text.

DeveloperJuly 11, 2026

Complete Guide to PDF Tools: Merge, Split, Compress & Convert

Everything you need to know about PDF manipulation in the browser. Learn how to merge, split, compress, and convert PDFs — no software install, no upload, fully private.