The 15 Best Free Sci-Fi Movies You Can Stream Online Right Now

Want to watch sci-fi movies online? These excellent free sci-fi movies can be streamed right now, and you won't have to pay a single cent.

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The "streaming wars" have ruined the convenience of online streaming. All the good stuff used to be on one or two streaming platforms—now all that content is scattered across dozens.

If you don't want to pay for several different streaming services, we don't blame you. I personally pay for three of them, and I'm reluctant to add any other streaming platforms without dropping one.

One option is to rent individual movies online, which only costs a few dollars each time and frees you from having to juggle several subscriptions or commit to a particular streaming platform.

Or you can stick with movies that are free to stream online! There are plenty of excellent sci-fi movies you can watch online for free, as long as you're willing to put up with a few ads through the runtime.

Don't have time to browse yourself? Here are our picks for the best free sci-fi movies you can stream right now!

15. Attack the Block (2011)

Attack the Block is a sorely underrated British sci-fi movie with plenty of comedy mixed in. When an alien invasion hits South London, a gang of teen thugs strike an unusual alliance with a young woman in an effort to fend off the bloodthirsty aliens.

John Boyega and Jodie Whitaker manage to elevate this sci-fi romp into a movie that's ways better than it deserves to be. Non-Brits may want to watch with subtitles, as the heavy accents and slang could be hard to parse—especially during action-packed scenes.

14. Snowpiercer (2013)

In a post-apocalyptic future that's been ravaged by climate change, all life on Earth has died except for the humans aboard the Snowpiercer—a train that's ruled by a stark caste system—and one passenger rises up to lead a rebellion.

Directed by Bong Joon-Ho (the creative mind behind the global sensation Parasite), Snowpiercer features plenty of social commentary wrapped within its thrilling story. And with its all-star cast of Chris Evans, Ed Harris, Tilda Swinton, and more? Simply excellent.

13. The Hunger Games (2012)

In a post-apocalyptic future where society is splintered into Districts, representatives from each District are selected every year to face off in a televised battle royale to the death—with victors winning the privilege to escape poverty and live a lavish life.

Despite how the sequels fell off, the first entry in The Hunger Games is a solid and entertaining story that stands well enough on its own. The characters are likable enough, but its the worldbuilding that stands out.

12. Cube (1997)

When six strangers wake up and find themselves in a strange maze of booby-trapped rooms, they have to figure out what's going on, how to escape, and how far they're willing to go in order to survive.

If nothing else, Cube serves as proof that a low budget doesn't matter all that much if you have a fun and intriguing premise. This mix of horror and sci-fi results in an experience that's as gruesome as it is cerebral. Weak stomachs may want to skip this one.

11. A.I. Artificial Intelligence (2001)

An advanced robot boy capable of complex thoughts is uniquely programmed to experience the emotion of love—and he yearns to become a "real boy" so that he can win the love of his human mother.

Yes, that's the boy from The Sixth Sense! Haley Joel Osment puts in a great performance here, arguably better than the one in The Sixth Sense. With spectacular direction from Steven Spielberg, A.I. Artificial Intelligence is a solid movie that's sadly underrated.

10. Timecrimes (2009)

While taking a break from home renovations, a man spots unusual activity in the woods around his house. When he investigates, he's caught up in an unfortunate series of events that send him back in time by one hour. Now he has to figure out how to break the time loop.

Timecrimes is one of the best movies about causal time loops, as it goes one step further than most movies. (I won't spoil in what way!) Note that this is a Spanish-language film, so be prepared to read subtitles—the dubbed version lacks much of the oomph.

9. Coherence (2013)

Coherence is a low-key cerebral sci-fi thriller about a group of friends having a dinner party that goes wrong. When an unknown comet passes overhead and causes a power blackout, reality is warped and mysterious events begin taking place.

This indie sci-fi film is everything that a low-budget flick should be: clever premise, smart direction, and sharp writing that leads to a powerful climax. It starts off a little slow, but if you can make it through the first act, you'll be well-rewarded.

8. Galaxy Quest (1998)

Galaxy Quest is a sci-fi comedy movie that parodies Star Trek and other sci-fi TV shows of the 90s. It features the cast of a TV show called "Galaxy Quest" who are visited by aliens and entangled in an actual galactic conflict of epic proportions.

Despite the nerdy bent, Galaxy Quest is such a great film that it even drew acclaim from mainstream audiences. Starring Tim Allen, Sigourney Weaver, and Alan Rickman, the humorous plot and characters are sure to leave a lasting impression.

7. Robocop (1987)

Robocop is one of the most iconic sci-fi movies of the 80s, featuring a murdered cop who's resurrected in the form of a cyborg. As he delivers merciless judgment against criminals, Robocop struggles with the vestiges of his own humanity within him.

The film uses its action-heavy premise to explore themes of identity, corruption, and criminal justice. It holds up well today, even if the overall aesthetics feel dated.

6. The Butterfly Effect (2004)

Twenty-year-old Evan has always experienced random blackouts throughout his childhood. Now, as an adult, his mind can travel back in time and occupy his younger self. He uses this power to change the past, but there are always unpredictable results on the present.

Deviating from his usual comedic roles, Ashton Kutcher puts in a surprisingly hard-hitting performance as he navigates all the alternate timelines that come from his character's decisions. It's a dark and traumatic film, so be prepared if you watch it.

5. Gravity (2013)

Two astronauts are left stranded in space when their Space Shuttle is destroyed, and they must use their brains to survive and make their way back to Earth in one piece.

Between Alfonso Cuaron's excellent direction and the incredible special effects, Gravity is as much a visual experience as it is a thrilling modern-day sci-fi thriller. If you can watch it in 3D, definitely do it! But even if you can't, it's absolutely worth a watch.

4. Moon (2009)

Sam Bell is an astronaut who's mining an alternative fuel source on the dark side of the Moon. He's all alone except for his robotic companion, GERTY, and has limited contact with Earth. Toward the end of his three-year deployment, he has a mental breakdown.

Moon is an eerie yet thoughtful example of hard sci-fi done well. There's a claustrophobic feel to the film that drives home the loneliness of Sam Bell and amplifies the strangeness of his situation. A must-watch for fans of character-driven science fiction.

3. The Man From Earth (2007)

Retiring college professor John Oldman gathers his colleagues for a farewell party, then drops a bombshell: he's actually a Cro-Magnon who's 14,000 years old, and he has lived through humanity's most important historical events.

The Man From Earth is the embodiment of sci-fi thought experiments. Most of the film takes place in John Oldman's house and is comprised of dialogue between him and his colleagues, with much of the dialogue taking the shape of intellectual arguments.

It'll definitely leave you scratching your head as you contemplate the ideas it puts forth, but don't take that to mean it's boring. It's surprisingly engaging, and it feels very much like a stage play that's been recorded for viewing as a movie.

2. Donnie Darko (2001)

A troubled teenager named Donnie receives a visit from a mysterious man in a grotesque rabbit costume, who tells him that the world is going to end in 28 days. That man begins to manipulate Donnie into commiting crimes.

Donnie Darko is not an easy movie to watch or comprehend, but it's the kind of philosophical movie that trusts the viewer to think about everything that's shown on screen and arrive at their own conclusions about what it all means.

Because of this, Donnie Darko has become a cult classic. You'll need to pay attention—and you may even need to watch it a few times.

1. Her (2013)

Her is a romantic drama that centers on a man who's been putting off divorce with his wife. When he decides to upgrade his computer and enable the AI-powered virtual assistant, he discusses his life with her—and eventually falls in love with her.

There's a lot of depth to this movie with a simple (and even clichéd) premise. Spike Jonze's smart direction, Joaquin Phoenix's soulful performance, and the delicate writing result in a story that's tender, seductive, and borderline terrifying.

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