The present invention provides an apparatus and method for testing seal strength and integrity of packages and for testing container and lid integrity, during an on-line production processing environment. Air pressure is introduced in a unique way to test the container and/or container seal in an additional step of an otherwise typical processing environment. A computer may be in communication with the testing sensors to control the processing in the event a failure is detected. The present invention provides a way to meet the continuously increasing line speed in form, fill and seal production processes with a unique ability of having complete package integrity testing for any odd shapes and package combinations.