Five free tools for invoices, images, QR codes and dates. Enter or select data in your browser, check the result, then save what you need. Read the instructions on each tool for its limits.
Build a simple invoice with line items, a discount, one tax rate and a live preview. Use the browser print route to save a PDF, then check the file and your own invoice register.
Reduce still-image sizes by quality, target size or maximum width. Compare the result and check dimensions and bytes before using it in an upload form.
Encode a link or other supported text as a static QR code. Download an image and test the payload, destination and final printed size before sharing.
Calculate calendar age, the interval between dates or an age gap. Check the stated month-end and leap-day convention when another institution uses a different rule.
Compare birth and reference dates, with an optional illustrative prematurity adjustment. This is general date information, not clinical assessment or a test-specific scoring service.