Abstract We have developed a reel-to-reel critical current density ( J c) measurement system based on the permanent magnet method and measured the J c of long stretches of HTS-coated conductor tape. This system has two kinds of measurement mode: a standard mode in which the measurement magnet moves, and a simple mode in which the measurement magnet is fixed. We showed experimentally that the simple mode can measure the J c of coated conductor at 6 m/h and that the standard mode can measure the J c of coated-conductor tape at 0.6 m/h. The measurement result obtained with the simple mode was similar as a result of the standard mode that can estimate the J c of a tape. This means that the system using the simple mode can evaluate the J c of a tape rapidly. This system also distinguishes localized defect like scratches or cracks. These results are promising for in-line evaluation of HTS coated conductors.