These adjustable rods, equipped with rubber end caps, utilize spring-induced tension to secure themselves against a window frame or wall, and can hold up to 20 pounds of weight.
However, they come in only a few basic colors and can only be installed between two vertical spaces. Additionally, they may not be suitable for larger windows or heavy curtains.
If tension rods don't suit your needs, adhesive hooks provide another no-drill option. You can affix these removable hooks to your wall and place the curtain rod
Magnetic rods are yet another alternative. They attach to metal window frames without drilling, but may be prone to shifting around and aren't suitable for heavy curtains.