Systems and methods for custom functional patterns for optical barcodes are provided. In example embodiments, image data of an image is received from a user device. A candidate shape feature of the image is extracted from the image data. A determination is made that the shape feature satisfies a shape feature rule. In response to the candidate shape feature satisfying the shape feature rule, a custom graphic in the image is identified by comparing the candidate shape feature with a reference shape feature of the custom graphic. In response to identifying the custom graphic, data encoded in a portion of the image is decoded.