Free-space optical communication (FSO) can achieve fast, secure and license-free communication without physical cables, providing a cost-effective, energy-efficient and flexible solution when fiber connection is unavailable. To achieve FSO on demand, portable FSO devices is essential for flexible and fast deployment, where the key is achieving compact structure and plug-and-play operation. Here, we develop a miniaturized FSO system and realize 9.16 Gbps FSO in a 1 km link, using commercial single-mode-fiber-coupled optical transceiver modules without optical amplification. Fully automatic 4-stage acquisition, pointing and tracking (APT) systems are developed, which controls the tracking error within 3 μrad, resulting in an average link loss of 13.7 dB. It is the key for removing optical amplification, hence FSO is achieved with direct use of commercial transceiver modules in a bidirectional way. Each FSO device is within an overall size of 45×40×35 cm³, and 9.5 kg weight, with power consumption of ~10 W. The optical link up to 4 km is tested with average loss of 18 dB, limited by the foggy test environment. With better weather condition and optical amplification, longer FSO can be expected. Such portable and automatic FSO system will arouse massive applications of field-deployable high-speed wireless communication in the future.