<p>The electrochemical reduction of CO₂ offers a promising route to valuable fuels; however, stable performance is hindered by gas–liquid transport limitations in the cathode gas diffusion electrode (GDE), which are directly affected by GDE compression. Here, we showed that operating an alkaline zero-gap CO₂ electrolyzer at a compression ratio (CR) of 10% achieved higher CO faradaic efficiency compared to CR = 20% and 30%. The improved performance is attributed to the fewer obstructions to gas transport in the 10% compressed cathode GDE, as evidenced by lower quantities of flooded anolyte and salt precipitates observed via synchrotron X-ray radiography. Less salt precipitate formation in the cathode at CR = 10% is further demonstrated by an 82% smaller mass transport resistance compared to CR = 30%, a result attributed to larger pores in the less compressed GDE that mitigate anolyte entrapment. Additionally, lower amounts of anolyte are observed at the cathode flow field–GDE interface at CR = 10%, whereas at CR = 30%, excess liquid at this interface led to CO₂ gas inlet blockage and cell voltage instabilities. As such, operating the CO₂ electrolyzer at lower CRs is recommended to facilitate gas–liquid transport within the cathode GDE and thereby improve overall cell performance.</p>