Methods and apparatus are disclosed to measure exposure to streaming media using media watermarks. An example apparatus includes a transcoder to transcode media into a streaming format, a media identifier to extract a watermark from the media, the watermark indicative of media identifying data, determine a source address at which the media will be hosted, and generate metadata of the media. The example apparatus further includes a reference database to store the metadata, a media transmitter to transmit the media to the media device in response to a first request for the media. In some examples, the media includes instructions to (1) determine a source Uniform Resource Locator, (2) determine a current playback time of the media, and (3) transmit a second request for metadata of the media. Example systems, methods, and apparatus disclosed herein enable a single set of monitoring instructions to be operated on multiple different devices and/or browsers.