Abstract: A method of determining position and dimensions of webpage elements includes inserting test border code around certain elements of content in existing content code. The resulting content code including the test border code is rendered by a content-rendering application. A screen capture image of the rendered content is obtained, and the dimension and/or position of a rendered test border is obtained by analysis of the screen capture image. The dimension and/or position is compared respectively with a reference dimension or position to obtain a dimension difference and/or position difference. If the difference satisfies a predetermined condition, a test parameter corresponding to the element is adjusted based on the difference. In certain embodiments, the non-border elements are removed from the screen capture image.