A number of scenes and lines have been removed, mostly quips, gags and awkward lines that were added in the film by way of reshoots. Among the most notable removed scenes are the prologue phone footage with Superman talking to a bunch of children and the gag with Flash faceplanting on Wonder Woman. Deleted Scenes and Missing Trailer Scenes were added, and the film has been rescored using compositions by Hans Zimmer, Junkie XL and Rupert Gregson-Williams from Man of Steel, Batman v Superman: Dawn of Justice and Wonder Woman for the sake of restoring thematic continuity.
Tropes different from the vanilla film include:
- All Myths Are True: The missing trailer scene with Cyborg saying "I heard about you, didn't think you were real" to Batman has been added.
- Body Horror: The footage from Batman v Superman: Dawn of Justice that showed a heavily amputated Victor Stone being painfully turned into Cyborg by a Mother Box is used when Diana is contacted by Cyborg, instead of the footage seen in the theatrical version of Justice League, in which Victor was much less amputated. This was done to fix a Series Continuity Error.
- Bookends: Has one with Man of Steel. The deleted scene of Superman returning to the Kryptonian ship and coming out of it with his suit on has been added, with his resurrection now forming a parallel with his symbolic "birth" — the first time he put the suit on and learned to fly — in Man of Steel.
- Flashback: Some scenes from Man of Steel and Batman v Superman: Dawn of Justice have been reworked as flashbacks and woven into Justice League scenes:
- Clark has memories from his battle against Doomsday resurfacing when he contemplates the remains of his monument in Metropolis after being resurrected. The voice of his Man of Steel self learning his real name also pops up in his mind during the fight against the nascent Justice League when Wonder Woman lassoes him, calls him "Kal-El" and urges him to remember who he is. He also has a flashback of his voice as he was at the mercy of Batman during their fight in Batman v Superman: Dawn of Justice when seeing the Dark Knight again.
- When Clark reunites with Lois and comes back at the Kent farm with her, he now has happy flashbacks of both the time when he and Lois Lane became lovers and his childhood.
- Flashforward: When Cyborg is trying to separate the Mother Boxes, he has visions of mass destruction of cities (the footage is taken from Watchmen) and visions of Batman's Bad Future nightmare from Batman v Superman: Dawn of Justice.
- Greater-Scope Villain: Cyborg has a vision of Darkseid when trying to separate the Unity.
- He's Back!: The deleted scene with Superman eventually returning with his suit on and talking to a surprised Alfred has been added.
- Instant Armor: Darkseid's armor assembles itself on him in Cyborg's vision. The footage is taken from the Injustice 2 Pre-Order Trailer.
- Leitmotif: For the theatrical version, Danny Elfman scrapped the themes Hans Zimmer and Junkie XL composed for Batman and Superman, and used a truncated orchestral version of the Wonder Woman theme. This fan edit puts the Zimmer and Junkie XL themes for Superman, Batman and (electric cello version) Wonder Woman back in, as well as a few other tracks such as "Look to the Stars" (Krypton's theme) and "This Is My World" (Superman's sacrifice and the mourning by Lois in Batman v Superman).
- Now It's My Turn: The missing trailer scene with Batman saying "My turn!" then shooting at the Parademons with the Nightcrawler has been added to the battle in the tunnels, replacing the "Sorry guys, I didn't bring a sword" reshoot and quip.
- Powered Armor: The deleted scene with Superman returning to the Kryptonian ship and looking at armors and suits on display (including a Kryptonian armor/space suit) has been added.
- Series Continuity Error: Specifically averted by this fan edit. Several moments from the theatrical version of Justice League that contradict events from Batman v Superman: Dawn of Justice have been fixed to restore continuity with the latter.
- The most notable has Cyborg stating that the Mother Box his father possesses activated itself for the first time after the death of Superman. It has been removed in this edit. The Mother Box clearly activated itself to create Cyborg's cybernetic body BEFORE Superman's death in Batman v Superman: Dawn of Justice as shown in the stolen "metahumans" footage Diana watches before taking part to the battle against Doomsday.
- The other continuity error that has been fixed is detailed in Body Horror above, essentially the fact that pre-cybernetic body Cyborg looks somehow less amputated in the footage shown in the theatrical cut of Justice League than he was in the footage from Batman v Superman: Dawn of Justice.