About Z Tools
An independent utility project built around useful workflows, explicit processing boundaries, and reproducible documentation.
Tools first, explanations second
Z Tools exists for small tasks that interrupt development and content work: inspect a JWT, clean JSON, hash a file, encode a URL, generate a QR code, compare color contrast, or prepare an image. The goal is not to become the largest tool directory. The goal is to make a smaller set of tools useful enough that their behavior, limits, and privacy model are easy to understand.
Most primary transformations are local
Ten tools perform their primary transformation in browser JavaScript. The Image Compressor is intentionally different: it uploads an image for temporary PHP GD processing, uses session-bound randomized filenames, and serves results through an expiring protected download flow. That exception is labeled on the tool and in the Privacy Policy rather than hidden behind a blanket “nothing leaves your device” claim.
Tests live beside the product
The source tree includes bounded offline verification scripts and raw results for Base64 overhead, JSON parser edge cases, SHA-family reference timing, identifier splitting, WCAG contrast math, and—when the environment provides PHP GD—image codec output sizes. Results include their environment and limitations. They are not exposed as public stress-test endpoints.
A deliberately simple stack
The site uses PHP, native CSS, native JavaScript, Apache rules, Web APIs, and a small set of vendored libraries for specific jobs such as QR generation/scanning, Markdown rendering/sanitization, MD5 compatibility, and image export. There is no front-end build pipeline required to deploy the site.
Public changes and contact
Meaningful product, privacy, content, and security changes are recorded in the changelog. If a result looks wrong, a browser edge case fails, or a page overstates what it does, use the Contact Form. Z Tools does not publish personal contact details or response-time promises.