About Us
UsefulShelf is a lightweight platform aggregating common online tools, focused on instant use and clear reliability.
What this site is for
UsefulShelf helps people quickly work with text, images, PDFs and everyday calculations. Each tool has controls, examples and limitations for a specific task, rather than just a feature name.
Start with a task
Start with the JSON formatter to inspect API data. Resize or compress image attachments before arranging them into a PDF. After generating a QR code for print, use the parser to inspect it. Combine tools around your task.
Maintenance and corrections
UsefulShelf maintains this site. Contact contact@usefulshelf.com for product matters or feedback@usefulshelf.com for tool issues. Include the page address, a sanitized sample and expected result. There is no guaranteed response time.
How references are checked
References are checked against the current implementation, with regression checks for deterministic encoding and conversion examples. Network queries, random outputs and file encoding depend on conditions, which the pages explain. Report reproducible discrepancies so they can be corrected.
Sources and scope
Pages involving standards link to original references, such as Chinese adult BMI categories and W3C text contrast criteria. This site does not provide medical diagnosis, financial advice or official certification. Review important output within the stated scope.
Local processing and external services
Most text, image and PDF tools run in the browser. Translation, exchange rates, weather, IP lookup and AI generation need network services. Tasks, schedules and some settings are saved in this browser. See the privacy policy for data flows and controls.