Hips that feel tight usually reflect a mixture of long hours spent in flexion, limited exposure to end range, and poor control there, rather than muscle that is literally too short. Combining mobility drills with strength through range typically changes the sensation faster than stretching alone.
The feeling of tightness is produced by the nervous system and correlates poorly with actual tissue length. People with substantial passive range often report feeling tight, and the sensation frequently reflects a lack of control or stability at end range. This is why hard stretching sometimes provides relief for an hour and changes nothing by the next day.
Pair a mobility drill with a strength exercise that uses the range you just opened. For example, a couch stretch or half-kneeling hip flexor stretch followed by glute bridges or hip thrusts. Add 90/90 hip switches for rotation and deep split squats to load the end range under control.
Ten minutes of drills does not undo nine hours of sitting. Standing up every 30 to 45 minutes, walking regularly, and varying your sitting position often produce more change than the mobility routine itself.
The sensation often improves within a couple of weeks; genuine range changes take longer. Consistency beats intensity here.
Pinching deep in the front of the hip, groin pain, clicking with pain, or restriction that is clearly hard and bony rather than stretchy warrants assessment by a physiotherapist. Hip joint structure varies considerably between individuals, and some restriction is anatomical rather than trainable. See The Hip: Mobility, Stability, and Power Transfer.