This study aimed to examine the performance of an anaerobic hybrid reactor (AHR) and an anaerobic continuous stirred tank reactor (CSTR) for treating high-strength fresh leachate. As the organic loading rate (OLR) was increased in both systems, the pH decreased, with the lowest pH corresponding to an OLR of 25-30 kgCOD/m³·d. The AHR system demonstrated instability in total volatile fatty acids when the OLR increased to 20 kgCOD/m³·d. The highest methane (CH4) content was achieved when the OLR was 15 kgCOD/m³·d. Moreover, the AHR showed excellent sediment retention. When the OLR increased, volatile suspended solids (VSS) in the system increased. The CH₄ content tended to increase as the OLR increased up to 20 kgCOD/m³·d. The highest CH₄ content in the AHR was 68%, which was higher than that of the CSTR. The CSTR could not produce biogas when the OLR was 20 kgCOD/m³·d. The optimal OLR for the operation of AHR and CSTR treating fresh leachate was found to be 15 and 10 kgCOD/m³·d respectively.