Production notes

Jonathan Demme was originally attached to direct the film and considered Harrison Ford for the role of Will Dormer. According to Christopher Nolan, he became aware of the original Norwegian film even before the release of his directorial debut Following, and sought to remake it after watching it twice.

Insomnia has Robin Williams playing a villain, deviating from the comedic roles for which he was earlier known. Regarding his decision to cast Williams, Nolan said, "I think [audiences] will come away feeling like they have seen a 'new' Robin Williams. Seeing Robin Williams doing something they would have never imagined that he would or could do."

Nolan on Williams's acting: What I thought of Robin, was, well he is an extraordinary guy to work with and he really gave what I consider to be a flawless performance. I wound up watching the film hundreds of times as we cut it, and I never hit that point with the performance where you start to see the acting. Most performances, at a point, bits start to peel off and away, but with Robin's he was very much in that character. Not that he's a very dark person to work with – he's very lively and friendly and amusing to work with. He really found something within himself. I think it's a very underrated bit of work on his part. In 2026, Nicolas Cage told The New York Times that he was offered a role in the film but he declined; he did not say which part he was offered.

Insomnia was filmed over a three-month period from April to June 2001. The opening aerial scene was filmed over the Columbia Glacier near Valdez, Alaska, and the float plane approach was over the Portland Canal near Hyder, Alaska, and Stewart, British Columbia. The town of Nightmute, Alaska, was primarily filmed in and around Squamish, British Columbia, including the hotel/lodge, police station, high school and cemetery. The scene in which Dormer shoots his partner on the rocky beach in the fog was filmed at Clementine Creek in Indian Arm, outside of Vancouver. The village of Umkumuit, where Finch's apartment is located and where the log-chase scene occurs, was filmed on Vancouver Island in Port Alberni. The waterfall road scene in which Dormer is on his way to Finch's lake house and spins his car 180 degrees was shot in front of Bridal Veil Falls on the Richardson Highway near Valdez, Alaska. The final scene, on the fictional Lake Kgun at Finch's lake house, was filmed on the northwest end of Strohn Lake in Bear Glacier Provincial Park, outside of Stewart, British Columbia. For this final scene, the film crew constructed Finch's lake house and dock from scratch, and disassembled and removed it after filming was completed in June 2001.

On review aggregator Rotten Tomatoes, the film holds an approval rating of 92%, based on 203 reviews, with an average rating of 7.80/10. The site's critical consensus reads: "Driven by Al Pacino and Robin Williams's performances, Insomnia is a smart and riveting psychological drama." On Metacritic, the film holds a weighted average score of 78 out of 100, based on 37 critics, indicating "generally favorable" reviews. Audiences polled by CinemaScore gave the film an average grade of "B" on a scale of A+ to F. Roger Ebert of the Chicago Sun-Times said, "Unlike most remakes, the Nolan Insomnia is not a pale retread, but a re-examination of the material, like a new production of a good play." Erik Skjoldbjærg, the director of the original film, said of Nolan's reinterpretation:

It was quite close, stylistically, to the original. I felt lucky that it's such a well crafted, smart film and that it had a really good director handling it, because as a remake I think it did really well, and it doesn't hurt any original if a remake is well done. So I felt I was lucky that Christopher Nolan took it upon himself to do it. Taste of Cinema complimented Nolan for being able to "capture the excitement of the original while still setting it apart as a notable film itself". IndieWire included Insomnia in their "10 Remakes of Classics by Great Auteurs" list, writing, "Nolan shifts the moral ground from the snowballing moral corruption of the original to shades of guilt and accountability and Pacino's increasingly bleary and hallucinatory perspective becomes an evocative metaphor for his struggle."

Later, Nolan singled out Insomnia as his most underrated film:I'm very proud of the film. I think, of all my films, it's probably the most underrated. [...] The reality is it's one of my most personal films in terms of what it was to make it. It was a very vivid time in my life. It was my first studio film, I was on location, it was the first time I'd worked with huge movie stars. [...] That's not really for me to say, but every now and again I meet a filmmaker and that's actually the film that they're interested in or want to talk about. Yeah, very proud of the film.