BrandonHabes’s review published on Letterboxd:
JULES AND JIM is essential, seminal, magical French New Wave. This puppy floats on a gleam of cool, flies like a dream, and feels like a valentine so thoroughly demented on poetry, art, books, but especially great friendship. It's the gold standard for cinematic threesomes. Perhaps even the advent for 60s hippies and flower children to blossom. Truffaut captures something so joyful, so tragic, maybe even allegorical, especially in the way he frames his three lovers, who together move from seasons of warmth and levity into dark places of grief and despair. Jules, Jim and Catherine form a love triangle of romance and disappointment. Their free-spirited passion for each other forms a unique, playful, but ultimately frightening bond, one that lyrically joyrides through all sorts of adulting rituals and historical spaces. It's about friends growing older, and perhaps wiser, as they realize the morning of their happiness is now over, and the evening of sadness that soon awaits them. By passing through this complicated relationship we equally, even symbolically, pass through the emotional warmth of a prewar society, the assault of WWI, the premonition of fascism, to finally the rise of diabolical Nazism.
All of these threads are elliptical in nature (you see them in the periphery of your vision ) but they still work to elevate the narrative beyond a simple coming-of-age menage à trois. Equal parts comedy and tragedy, it's the kind of film that expresses the joy of filmmaking, even as it refuses to be sentimental in its approach. Truly one of the great wonders of Truffaut's filmography thus far.