Articles

Guides, tutorials, and deep-dives on the tools we build at Toolhub.

• Prompt versioning: keep your iterations honest

  2026-07-26

  Every team that ships LLM features eventually hits the same wall: a production prompt called v3-final-FIXED, no way to reproduce the eval from three weeks ago, and a slow drift toward worse output that nobody caught. This article lays out the minimum versioning discipline that prevents that — Git the prompts, couple them to evals, track cost-of-change, and chase clarity before cleverness.

• EXIF metadata: what your photos quietly leak about you

  2026-07-19

  EXIF metadata embeds far more than GPS coordinates: device serial numbers, software-edit trails, sometimes the owner's name. This article walks through the four main categories of leak, where stripping fails, and which platforms preserve metadata when you upload (more than you'd guess).

• Base64: when to use it, when it ruins your life

  2026-07-12

  Base64 encodes binary as text — useful for email attachments, JWT payloads, and small inline assets. It's also routinely misused for fake encryption, oversized inline images, API payloads that should be multipart, and URL params past the 2KB limit. This article covers when Base64 is the right answer and when it's the source of your performance bug.

• RPG damage formulas explained: subtractive vs divisive vs percent-resist

  2026-07-05

  Subtractive (D&D), divisive (Diablo), and percent-resist (MMO) — the three core damage formulas in RPG design, what each does to the player's experience, when each falls apart, and how to pick the right one for the game you're trying to build.

• VAT for digital products: the 101 indie sellers actually need

  2026-06-28

  EU VAT on digital products: the €10k threshold, OSS vs IOSS, when a Merchant of Record makes sense, country quirks, and the rules that change when a B2B buyer enters their VAT number. The decisions an indie seller actually has to make, plus the math at each scale.

• Citation styles cheat sheet: APA 7 vs MLA 9 vs Chicago vs Harvard (and when each is required)

  2026-06-21

  APA 7, MLA 9, Chicago, and Harvard are the four citation styles most likely to be required by an instructor or journal. Each has a personality, each has a domain where it's standard, and each has the specific rules that consistently trip up students. This article covers all four at the level you need to actually finish the assignment.

• Why browser-only tools matter for privacy (and why most "free online tools" sites aren't)

  2026-06-14

  Most "free online utility" sites quietly upload your input to a server, log it, and sometimes archive it for training data or resale. Browser-only tools don't have a server to upload to. This article defines the difference precisely and shows you how to verify it yourself.

• Compound interest: three myths that cost real money

  2026-06-07

  Compound interest math is taught as a single magic formula. In practice three persistent myths cause real harm to savings projections. This article dismantles each, shows the corrected math, and walks through three Toolhub tools to validate your own numbers.

• Token counting for LLM cost management

  2026-05-19

  Most LLM cost surprises come from one mistake: assuming a token is roughly a word. It isn't. System prompts on every request, JSON whitespace, tool-use schemas, and vision tokens add up faster than developers expect. Five places where the bill actually lives, with real numbers.

• JPG vs WebP vs AVIF: when to use each

  2026-05-16

  JPEG, WebP, and AVIF each win different fights — file size, compatibility, encode time, animation support. A practical guide to picking the right one without re-encoding your entire CDN.

• JSON: 5 common errors devs hit and how to fix them

  2026-05-16

  Trailing commas, single quotes, unquoted keys, comments, and unescaped characters cause the majority of "but it looks fine" JSON failures. Five concrete fixes, with code samples and a short RFC 8259 reference.