Guides

Short, practical write-ups on the things our tools deal with. Each guide explains how something works, shows real examples, and points out the mistakes people usually make. Most link to the tool that does the job, so you can try it right away.

• How to Write Good Alt Text (With Real Before and After Examples)

  Alt text rules that help screen reader users and search: what to describe, what to skip, when to leave it empty, with real examples.

  3 min read, updated September 26, 2026

• Why iPhone Photos Won't Open (and How to Convert HEIC to JPG)

  Why iPhones save HEIC, why Windows and websites reject it, and three fixes: convert the file, change the camera setting, or convert on transfer.

  3 min read, updated September 26, 2026

• JPG, PNG, WebP or AVIF? How to Pick the Right Image Format

  A practical guide to image formats: lossy vs lossless, and which suits photos, screenshots, logos and animation. Includes tips to avoid quality loss.

  3 min read, updated September 26, 2026

• What Your Photos Reveal: EXIF Data, GPS Tags, and How to Remove Them

  Photos can carry your location, device and timestamps. See what EXIF data is, how to check a photo, and how to remove it on any device.

  3 min read, updated September 26, 2026

• robots.txt and llms.txt: What Actually Controls AI Crawlers

  Which AI bots exist (GPTBot, ClaudeBot, Google-Extended and more), what robots.txt can and can't do, and an honest look at whether llms.txt matters yet.

  3 min read, updated September 26, 2026

• LLM Tokens Explained: How to Estimate Your API Bill Before It Surprises You

  What a token is, why non-English text and code cost more, how input and output pricing works, and a worked example for estimating a monthly AI API bill.

  3 min read, updated September 26, 2026

• How to Check a Download with a Checksum (Windows, Mac, Linux)

  Compare a file's SHA-256 hash with the publisher's checksum. Commands for Windows, Mac and Linux, plus what a match does and doesn't prove.

  3 min read, updated September 26, 2026

• MD5 vs SHA-1 vs SHA-256: Which Hash Should You Use?

  MD5, SHA-1, SHA-256 and SHA-512 compared: size, speed, known weaknesses, and which to use for checksums, dedup or passwords (not plain hashes).

  3 min read, updated September 26, 2026

• What Base64 Is (and Why It Isn't Encryption)

  How Base64 works, why it makes data about 33% bigger, when to use the URL-safe variant, and why you should never treat it as a way to hide secrets.

  3 min read, updated September 26, 2026

• URL Encoding Explained: Which Characters to Escape and Why

  Why URLs turn spaces into %20, which characters are reserved, the difference between encodeURI and encodeURIComponent, and how to avoid double encoding.

  4 min read, updated September 26, 2026

• UUID v1, v4, v5 and v7: Which Version Do You Need?

  What each UUID version is for, why random v4 IDs can slow down database indexes, when v7 is the better pick, and how name-based v5 IDs stay the same every time.

  4 min read, updated September 26, 2026

• Strong Passwords in 2026: Length, Passphrases, and What to Stop Doing

  What makes a password hard to crack, how many bits of entropy a passphrase has, what current NIST guidance says, and a simple setup that works for real life.

  3 min read, updated September 26, 2026