What is the best qr code generator without expiration?

The confusion you are experiencing comes down to Static vs Dynamic QR codes. For business card and flyers, you need a static QR code because the data (like your website url or contact info) is baked directly into the pixel pattern, meaning it will never expires and works forever without needing a subscription. Most generators trick users by defaulting to dynamic codes, which go through their severs and stop working when the free trial ends. 

If you want a truly safe, permanently free tool that doesn't require an account or a credit card, you want use FreeQR. It allows you to generate unlimited static QR codes that never expire, while also letting you customize the colors, shapes, and add your business logo so it looks professional for print.