There is very little capability difference to decisively separate the Rafale and the Eurofighter. The EF is more oriented to the air to air role with a larger nose, higher engine thrust and an airframe which was designed around ensuring maximum carriage of air to air missiles (4 BVR weapons at all times).
But the Rafale is not necessarily inferior-it’s smaller (and some say more stealthy) and its close-coupled canards would help in a low-altitude dogfight. And in the days of datalinks and AEW, the RBE-2’s range to utilise the Meteor or the Mica is not leagues behind the Typhoon. And assuming it get’s an engine upgrade, it’s high speed/high altitude performance would also improve.
But that’s beyond the point; both fighters could only do so much against a genuinely stealthy fighter (and we don’t know if the J-20 will turn into that) since their basic configuration is essentially the same. As Spetznaz said a while back-they are twins.