Guides

In-depth guides on file formats, data formats, and the tools that work with them.

• Base64 Isn't Encryption: What It's Actually For

  Base64 turns binary data into text-safe characters so it survives systems built for text — it hides nothing and adds no security.

• The 5 JSON Errors That Break Most Parsers

  JSON looks like JavaScript but follows a stricter grammar — these are the five mistakes that account for almost every "unexpected token" error.

• The CSV Edge Cases That Break Naive CSV-to-JSON Converters

  CSV has no single formal spec — commas inside quoted fields, embedded newlines, and inconsistent encodings each break a simple split(",") parser differently.

• Why iPhone Photos (HEIC) Won't Open Everywhere

  HEIC compresses better than JPEG using a newer, patent-encumbered codec — which is exactly why so much software still can't open it.

• How "Age" Is Actually Calculated (and Where the Off-by-One Bugs Hide)

  Age isn't just "this year minus birth year" — the borrow-a-day-from-the-month logic, leap years, and Korea's separate age system each break naive math differently.

• How a Password Generator Actually Picks Random Characters

  The security of a generated password depends entirely on where its randomness comes from — and Math.random() is the wrong answer.

• How Much Data Can a QR Code Actually Hold?

  A QR code's capacity depends on its version (grid size), its error correction level, and what kind of data you're encoding — and the three trade off directly against each other.

• 3 Ways to Remove a Background From a Photo (and When Each One Fails)

  Chroma key, edge detection, and ML segmentation solve background removal differently — and each one breaks on a different kind of photo.

• What's Actually Hiding in Your Photo's EXIF Data

  Every photo a camera or phone takes carries metadata beyond the pixels — including, by default, the exact GPS coordinates where it was taken.

• Why Won't My PDF Get Any Smaller?

  Most of a PDF's size lives in three places — images, fonts, and structure — and each one has a hard floor that no compressor can push past.