On 31 July Captain W. D. Stephens relieved Lambe. The end of the war several weeks later meant that there was no longer any urgency in refitting the "Illustrious" in time to participate in the invasion of the Japanese Home Islands and the Admiralty decided that she would become the Home Fleet training and trials carrier. Her catapult was upgraded to handle heavier aircraft, her flight deck was further improved, and her radar suite was modernized. She began her postrefit trials on 24 June 1946 and flying trials the following month. She relieved as the trials carrier in August and conducted trials on Firefly FR.4s, Firebrand TF.4s, de Havilland Sea Mosquitoes and de Havilland Sea Vampires over the next several months. Captain Ralph Edwards relieved Stephens on 7 January 1947.