In 1947, Variety magazine said "Hitchcock could have chosen a more entertaining subject with which to use the arresting camera and staging technique displayed in Rope." The next year, Bosley Crowther of The New York Times said the "novelty of the picture is not in the drama itself, it being a plainly deliberate and rather thin exercise in suspense, but merely in the method which Mr. Hitchcock has used to stretch the intended tension for the length of the little stunt" for a "story of meager range". Nearly 36 years later, Vincent Canby, also of The New York Times, called the "seldom seen" and "underrated" film "full of the kind of self-conscious epigrams and breezy ripostes that once defined wit and decadence in the Broadway theater"; it's a film "less concerned with the characters and their moral dilemmas than with how they look, sound and move, and with the overall spectacle of how a perfect crime goes wrong".
In the Time magazine 1948 review, the play that the film was based on is called an "intelligent and hideously exciting melodrama" though "in turning it into a movie for mass distribution, much of the edge [is] blunted."
Much of the play's deadly excitement dwelt in [the] juxtaposition of callow brilliance and lavender dandyism with moral idiocy and brutal horror. Much of its intensity came from the shocking change in the teacher, once he learned what was going on. In the movie, the boys and their teacher are shrewdly plausible but much more conventional types. Even so, the basic idea is so good and, in its diluted way, Rope is so well done that it makes a rattling good melodrama.
Roger Ebert wrote in 1984, "Alfred Hitchcock called Rope an 'experiment that didn’t work out', and he was happy to see it kept out of release for most of three decades," but went on to say that "Rope remains one of the most interesting experiments ever attempted by a major director working with big box-office names, and it's worth seeing [...]."
A 2001 BBC review of that year's DVD release called the film "technically and socially bold" and pointed out that given "how primitive the Technicolor process was back then", the DVD's image quality is "by those standards quite astonishing"; the release's "2.0 mono mix" was clear and reasonably strong, though "distortion creeps into the music".
In his article "Remembering When", Antonio Damasio argues that the time frame covered by the movie, which lasts 80 minutes and is supposed to be in "real time", is actually longer—a little more than 100 minutes. This, he states, is accomplished by speeding up the action: the formal dinner lasts only 20 minutes, the sun sets too quickly and so on.