If there's any reason flashbacks have become faux pas in modern writing it's because of the Saw series. Untangling the web of twist accomplices is the key to unlocking the chronological order of the Saw movie franchise. The only problem is the origin story is split across various movies.
The only proper way for it to all make sense is to order the entries by the flashbacks first, with the list of movies they occur in, then actually listing out the rest of the movies in order. The movies are always good blood-soaked fun, but there is so much story behind the gory surface of the series. Dissecting the chronological order of the Saw timeline is certainly difficult, but not impossible.
Backstory 1 (Saw IV & Saw VI)
It all starts with Saw IV where the audience meets John Kramer, an engineer, and his wife Jill. Jill was pregnant and opened up a drug clinic which a man named Cecil Adams tried to rob for another soon-to-be important character, Amanda, as revealed in Saw VI.
Cecil slams the door against Jill's stomach, causing a miscarriage. John drifted away completely traumatized from the event and eventually broke up with Jill. He isolated himself with his thoughts until he was diagnosed with cancer.
Backstory 2 (Jigsaw & Saw IV)
Being embittered by his wasted life, the future killer watched others closely and observed how they lived their lives. Seeing others waste their lives while his life was coming to an end depressed John. After being denied money for his cancer treatment by William Easton, in Saw II, John comes to an epiphany that spawns the development of his ideals.
In the Saw IV flashbacks, John designs his first traps for Cecil and in Jigsaw, Logan implies that he survived one of the earlier tests and became John's first apprentice, thus confusing the timeline even further at a late stage in the franchise.
Backstory 3 (Saw IV, Saw V, Saw II, & Saw VI)
In Saw IV's flashbacks, John adopts the idea of "Instant Rehabilitation one person at a time" and continues on his killing ways, using traps revealed in Jigsaw to be designed by Logan. John's eventually labeled the Jigsaw Killer by the media when his signature of jigsaw puzzle-like pieces of flesh being removed from the victims is discovered.
Jigsaw's controversy eventually leads–as revealed in Saw V–to a copycat killer in the form of a cop named Mark Hoffman who would become a very important character. Having kidnapped and blackmailed Mark, Jigsaw annexes him to his cause. Mark eventually designs traps to be used in the first movie, where the timeline does not get simpler. Prior to the first Saw movie, Amanda Young becomes the first known survivor of Jigsaw's games. As revealed in Saw II, she takes to him like a father figure and says his games benefitted her life, becoming another apprentice before the first movie even starts. As shown in Saw VI, Jigsaw then shows the "rehabilitated" Amanda to Jill, who essentially goes on to become another accomplice/apprentice.
Saw (2004)
● Available on HBO Max
Saw technically starts with Amanda kidnapping Adam Stanheight for the game. Jigsaw, however, also goes for kidnapping his doctor who diagnosed him with cancer, Lawrence Gordon. This movie introduces Jigsaw's ideas and blood-soaked games.
An important moment that leaves a lasting impact on future entries is Jigsaw helping the doctor and making him another accomplice, adding to the list of things that don't really make sense about the apprentices. This means that technically within the timeline, by the time that the events of the first movie take place, there are already 6 different Jigsaws.
Saw II (2005)
● Available on HBO Max
Another game is underway, with Amanda serving as a red herring. Eric Matthews is introduced as another victim who in the end gets kidnapped by Hoffman for a future game, as revealed in a flashback from Saw IV. Besides that, there isn't much that happens that is relevant to the overarching plot of the series.
The movie's point seemed to be about establishing that Amanda was actually evil, even if the story revolved around her getting a reckoning against Eric Mathews for wrongly accusing and jailing her for a crime.
Saw III (2006)/Saw IV (2007)
● Both movies are available on HBO Max
Saw III and Saw IV happen at the exact same time and follow two of John's protegees: Amanda's traps for Saw III and Mark Hoffman's traps for Saw IV. Amanda's games start off as a disaster because she no longer believes Jigsaw's traps actually change people, even though she was one of them, and starts making traps that are impossible to beat. Jigsaw eventually has to put her through a test so that a straight-up immoral murderer isn't in charge of his legacy, which she fails, getting them both killed.
Saw IV follows Mark Hoffman as he brings Eric back in for a test with David Riggs, a reoccurring SWAT member investigating Jigsaw. Mark eventually finds the bodies of Amanda and the original Jigsaw. The autopsy scene is actually the last scene in the canonical timeline for this film, culminating with Hoffman finding a tape inside Jigsaw's body telling him that he will be tested still.
Saw V (2008)
● Available on HBO Max
In Saw V, Jill is given a tape by the police from her dead serial killer husband with a list of instructions for her to follow, which come into play in the series again later.
The main plot of the movie follows the new Jigsaw following John Kramer's death in the concurrent timelines of Saw III and Saw IV, Mark Hoffman, in another game much like a child's first ride on Billy the puppet's creepy tricycle. The traditional shock twist ending sees Hoffman escaping police pursuit to set up the conflict in the next movie.
Saw VI (2009)
● Available on HBO Max
Following instruction meant for Jill from Saw V, Mark goes after the man who denied John his cancer money, William Easton. Mark lets Jill know he's taking over the position as Jigsaw, which does not ring well with her as she has instructions to kill him from John.
Fittingly this was probably the test John forwarned Hoffman about. William meets a horrible end and Mark goes back to the scene only to get jumped by Jill who puts him in a reverse bear trap, much like the one he designed for Amanda in the first Saw. However, Hoffman manages to escape it.
Saw 3D (2010)
● Available on HBO Max
Mark Hoffman and Jill Tuck are battling for the title of Jigsaw. The storyline in the Saw movies is finally starting to simple out. The game of the movie follows another person who is kidnapped for faking his survival of a Jigsaw game for fame and money, while Hoffman goes on the attack to find Jill, who is in police custody.
Jill outs Mark as Jigsaw which he counters by mowing through a police station to get to her and end her life in a Reverse Beartrap like she had tried to use on him. As it looks like Hoffman is about to get away with it all, Dr. Lawrence Gordon, from all the way back from the original Saw, reveals himself as a new apprentice and finds Hoffman, finally putting an end to him.
Jigsaw (2017)
● Available on Peacock
Jigsaw can be watched without prior knowledge of all the other movies, but still adds to the story slightly. It takes place 10 years after the events of Saw III and Saw IV, with another apprentice rising after Jigsaw's death.
Much like how the story went with Hoffman, the ending allows the killer to get away with the promise of more games to come. However, with no explanation regarding the surprise reappearance of Dr. Gordon in Saw 3D and all of the acolytes that he appears to be working with, fans were not sufficiently impressed and the franchise would ultimately decide to move even further into reboot territory for its next installment.
Spiral: From the Book of Saw (2021)
● Available for purchase on Prime Video
While Spiral: From the Book of Saw clearly links itself to the original Saw timeline, it is the most independent of the stories from the franchise so far. John Kramer is only mentioned in hindsight, appearing as a picture on an evidence board in what is just part of the puzzle leading to the new killer who's inspired by the methods of Jigsaw.
The new killer only targets people on–or retired from–the police force, bringing back the moral angle of the killings as it appears that the victims were all corrupt in some way. The movie doesn't place itself anywhere in particular in relation to the original Saw timeline, though it can be surmised that it takes place after Jigsaw and contains the most recent occurrences in the long-running serial killer/copycat saga.
Though the movie ends in typical fashion for the series, with a last-minute twist setting up future sequels, it remains to be seen whether Spiral will prove to be a more solid foundation for a future compared to Jigsaw.