Fluorescence lifetime imaging microscopy (FLIM) is a powerful imaging technique that provides molecular-specific insights by measuring fluorescence decay times. However, conventional FLIM systems are limited by slow imaging speeds and a lack of three-dimensional (3D) imaging capabilities. Recent advancements aim to improve FLIM's speed and 3D imaging. This review discusses progress in FLIM instrumentation and potential future directions. FLIM can be categorized into frequency-domain and time-domain methods. Frequency-domain FLIM uses modulated light to measure phase shifts and modulation depths, while time-domain FLIM uses pulsed lasers and ultrafast detectors to capture transient fluorescence signals. Both methods have limitations in speed and 3D imaging. To address these, researchers have developed high-speed FLIM techniques, including parallel detection and analog recording, which allow for faster imaging. Additionally, 3D FLIM has been improved through methods like light-sheet microscopy and tomographic imaging, enabling faster and more comprehensive data acquisition. Recent advances in high-speed FLIM include the use of time-correlated single-photon counting (TCSPC) and parallel detection to reduce dwell time and increase acquisition speed. Analog recording techniques also enable high-speed imaging without the need for photon counting. For 3D imaging, methods such as light-sheet microscopy and tomographic reconstruction have been employed to overcome the dimensionality gap and enable faster 3D FLIM. In addition, computational imaging has emerged as a promising approach, combining AI and deep learning to enhance FLIM performance. Advanced detector technologies, such as single-photon avalanche diodes (SPADs), have improved sensitivity and resolution. Furthermore, deep tissue imaging has been enhanced by using longer wavelengths in the near-infrared (NIR) range, which reduces scattering and allows for deeper penetration. Overall, advancements in FLIM instrumentation are enabling faster, more detailed, and more versatile imaging capabilities, with significant implications for biomedical research and clinical applications.Fluorescence lifetime imaging microscopy (FLIM) is a powerful imaging technique that provides molecular-specific insights by measuring fluorescence decay times. However, conventional FLIM systems are limited by slow imaging speeds and a lack of three-dimensional (3D) imaging capabilities. Recent advancements aim to improve FLIM's speed and 3D imaging. This review discusses progress in FLIM instrumentation and potential future directions. FLIM can be categorized into frequency-domain and time-domain methods. Frequency-domain FLIM uses modulated light to measure phase shifts and modulation depths, while time-domain FLIM uses pulsed lasers and ultrafast detectors to capture transient fluorescence signals. Both methods have limitations in speed and 3D imaging. To address these, researchers have developed high-speed FLIM techniques, including parallel detection and analog recording, which allow for faster imaging. Additionally, 3D FLIM has been improved through methods like light-sheet microscopy and tomographic imaging, enabling faster and more comprehensive data acquisition. Recent advances in high-speed FLIM include the use of time-correlated single-photon counting (TCSPC) and parallel detection to reduce dwell time and increase acquisition speed. Analog recording techniques also enable high-speed imaging without the need for photon counting. For 3D imaging, methods such as light-sheet microscopy and tomographic reconstruction have been employed to overcome the dimensionality gap and enable faster 3D FLIM. In addition, computational imaging has emerged as a promising approach, combining AI and deep learning to enhance FLIM performance. Advanced detector technologies, such as single-photon avalanche diodes (SPADs), have improved sensitivity and resolution. Furthermore, deep tissue imaging has been enhanced by using longer wavelengths in the near-infrared (NIR) range, which reduces scattering and allows for deeper penetration. Overall, advancements in FLIM instrumentation are enabling faster, more detailed, and more versatile imaging capabilities, with significant implications for biomedical research and clinical applications.