Phineas and Ferb Wiki
Phineas and Ferb Wiki

"Hey, Ferb! I know what we're gonna do today!"
— Phineas.

Almost every day during their summer vacation, Phineas Flynn and Ferb Fletcher have Big Ideas and go through with them. Some of the plans are used as a way of helping someone in need, while others are just to help them have the best possible summer ever, as described in "Rollercoaster" and "Rollercoaster: The Musical!".

List of Big Ideas

Main article: Big Ideas/Season 1
Main article: Big Ideas/Season 2
Main article: Big Ideas/Season 3
Main article: Big Ideas/Season 4

Movies and Crossovers

Episode Image Big Idea Disappearance Notes
Phineas and Ferb the Movie: Across the 2nd Dimension Platypult ready to be used.jpg
The boys made a platypult to play badminton with Perry. They then get off-course and crash into Dr. Doofenshmirtz's Otherdimensionator, leading into a grand adventure as they through a parallel universe with Agent P in agent form and try to defeat Alternate Doofenshmirtz.
Robot Riot
As Doofenshmirtz of the 2nd Dimension invades Danville of the 1st Dimension with his army of Norm Bots, Phineas and Ferb enter Perry's lair, to discover Perry has preserved many of their previous inventions with computer data, which is able to be replicated with special O.W.C.A. technology. The boys use their previous inventions alongside many of the kids of Danville to fight off the Norm Bots and save the Tri-State Area. Doofenshmitz-2 activates the Norm Bots' self-destruct, presumably destroying them.
"The Phineas and Ferb Effect" Screenshot 20190123-195148 YouTube.jpg
Murphy's Law Suit
After studying and collecting data on Murphy's Law, as well as learning about the Phineas and Ferb Effect, the brothers build a giant mech suit in Milo's likeness in order to defeat the Pistachions. The Murphy's Law Suit is able to aim Murphy's Law in any direction. In order for it to work, Milo, Phineas, and Ferb should be together in this machine.
Phineas and Ferb the Movie: Candace Against the Universe
After Such a Beautiful Day (10).jpg
Giant robotic clown
They build a giant clown that juggles the kids around. It gets turned into lint by Doofenshmirtz's power vacuum-inator and is sucked up by it.
CATU Enter Portal.jpg
Portal to Feebla-Oot.
After Candace and Vanessa get abducted by aliens, the gang build a portal to the planet where she is taken. Unfortunately, due to an ion barrier, it instead takes them to Doofenshmirtz Evil Incorporated. Lawrence goes through the portal, and ends up at D.E.I., which is on fire. His flaming newspaper somehow causes the portal to burn up, turn into ash, and then gets blown away by the wind.
CATU Candace Coffee Mug.jpg
Coffee mug for Candace
After seeing how upset Candace was about her summer, her brothers make her a special coffee mug that projects all the times they had fun together. N/A


Episode Image Big Idea
Camp Rock 2: The Final Jam Its On.JPG
"It's On" (Summer version)
Crossing over with the cast of Camp Rock 2: Final Jam, Phineas and Ferb directed the Summer version of the music video "It's On" from Camp Rock 2: The Final Jam, kicking off Disney Channel's Summer Vacation. The video ends with the entire party leaving the boardwalk.

Background Information

  • The plans the boys come up with can be described as impossible because they are accomplished in a very short amount of time (less than a morning {they use the invention in the afternoon, most likely}) and involve technology that has yet to exist in the real world: teleportation, mind-switching, time traveling... Phineas and Ferb do not think of their plans as impossible, just fun and great. When Isabella asks Phineas if building a time machine is "kind of impossible", he replies, "That's a possibility". ("It's About Time!")
  • The phrase "Big Ideas" references the advertising campaign that Disney Channel ran prior to the launch of the series in February 2008. For Phineas, it was "he thinks big". For Ferb, it was "he thinks how".
  • Despite Phineas saying that he likes to "keep moving forward", he actually has repeated his big ideas. Examples are the rollercoaster in "Rollercoaster", "Fireside Girl Jamboree", "Phineas and Ferb-Busters!", and "Rollercoaster: The Musical!"; the waterslide in "Leave the Busting to Us!" and "Elementary My Dear Stacy"; the molecular separator in "Split Personality" and "Canderemy"; and the time machine in "It's About Time!" and "Phineas and Ferb's Quantum Boogaloo."
  • Phineas and Ferb have been busted five times on-screen.
    • It was all Candace's dream in Perry's dream ("Phineas and Ferb Get Busted!").
    • Older Candace busted them while building the Rollercoaster, which has been undone by herself after she saw that this would lead to a dystopian society run by Emperor Doofenshmirtz. This happened in another universe. Later, Candace busted them by showing herself to future mom, but this has probably been undone by Isabella when she went back in time and made the entire episode undone during the credits. Along with the fifth time they were busted, this happened in another universe ("Phineas and Ferb's Quantum Boogaloo").
    • When they built a pioneer village, but that was undone when the acceleratorinator moves time backwards ("She's the Mayor").
    • Once Candace succeeds in busting them briefly, however her mother is hit with Doofenshmirtz's "Forget-About-It-Inator" repeatedly and by the time she is no longer being hit by the ray, Candace has ran off and the boy's invention isn't in view so she returns inside ("A Real Boy").
    • Linda "busts" Phineas and Ferb herself due to them leaving towels all over the ground. ("Love at First Byte")
  • However, there are other times where Phineas and Ferb's plots have been seen by their parents, a famous example being in "Dude, We're Getting the Band Back Together" among others, however they weren't "busted" for them (assuming "busting" implies that they were intentioned to get in trouble for whatever they're doing). Their dad has also seen and has been involved in some of their big ideas, but it doesn't seem he minds and Candace almost never gets her dad to bust them which implies the busting power is from their mom.
    • One famous example is during Mom's birthday, because on that day she saw everything they built ("Mom's Birthday")
    • Mom saw the teleporters but due to the effects of Doofenshmirtz's Shrinkinator, she thinks they're earrings the boys made her ("Does This Duckbill Make Me Look Fat?").
    • Their Mom actually sees Nosebud and says that it's "pretty cool" because it actually floats, but does not know about the station under it ("The Lake Nose Monster").
    • Mom saw the animal translator, only to her Phineas and Ferb were just using some sort of recording machine because it didn't work on Perry ("Interview With a Platypus").
    • Mom saw only the top portion of the fort (and not the other giant parts of it). Upon seeing this, she remarks on how Phineas and Ferb are "beginning to take an interest in building things" ("Thaddeus and Thor").
    • Mom saw Phineas and Ferb's creation, only Phineas and Ferb were gone and she thought it was some kind of modern art ("The Bully Code").
    • Mom saw Phineas and Ferb's hot air balloons, but believed them to be the boys himself because they were positioned in front of a clothing rack with their clothes, and her blurry vision made them appear to be the real boys ("Last Train to Bustville").
    • Mom actually saw Drusselstein stretching over Danville due to Baljeet's reality warping technology, but she assumes it's overcast ("The Doonkelberry Imperative").
    • Mom saw Phineas and Ferb's Backyard Hodge Podge made out of recycled parts, but thought she was hallucinating, and Candace cannot see it clearly after being hit by Doofenshmirtz's Eye Fog-inator ("Backyard Hodge Podge").
    • Mom saw the jumbotron to Phineas and Ferb's Ultimate Obstacle Course, but because of the picture of the boys on the monitor, she assumes it's just the boys and leaves ("One Good Turn").
  • Also, there are other times where the plots were sometimes seen by Phineas and Ferb's parents but the only one who got caught was Candace herself, a good example being in "The Best Lazy Day Ever", however Candace built a dinosaur slide in that episode.
    • They built the haunted house in "One Good Scare Ought to Do It!", but Candace was the only one scolded because whenever she tried to show it to Linda, it is gone and the only thing left was Baljeet, making it appear to Linda that Candace was insulting Baljeet, which she finds very rude of her.
    • They built something in "Perry Lays an Egg", but Candace was the one who got in trouble.
    • Linda only saw the top level of the boys' fort in "Thaddeus and Thor", because the boys had to turn the extension off due to zoning laws; however, Candace was the one scolded, because she literally "threw the groceries in the kitchen" and made a big mess, refusing to go anywhere until she does her chore properly.
    • Phineas and Ferb built a Latest Technology All-Terrain Vehicle in "The Secret of Success", but it was Candace who got into trouble as she said that she drove it herself and Mom grounds her thinking that she was driving a car without any adult surveillance.
    • Phineas and Ferb didn't do anything in "Candace Gets Busted". But when Mom and Dad see that Candace is having the party (the Intimate Get Together), Candace is the person busted.
    • They built ninja suits to stay quiet in "Quietest Day Ever", but because Candace kept disturbing Linda while she was taking her knitting test, Candace was the only one scolded.
    • Candace recorded the trip in "Meapless in Seattle" to save Meap on her phone to get busted along with her brothers, but had to sacrifice it to stop Mitch from escaping. Candace was the one who gets in trouble afterward for neglecting to take out the garbage.
    • They built extreme batting cages in "Return Policy", but at that time, Candace sneaks out of her shopping with Linda to go to the Extreme Water Park with Jeremy without even telling her, resulting in her punished after getting home.
    • They built a solar system race in "The Inator Method", but due to Candace causing a huge mess of the house due to multitasking with her Ducky Momo MMORPG, Candace was the one who was scolded.
  • Lawrence Fletcher has seen many of Phineas and Ferb's creations, but does not bust them and encourages them to be creative. This is probably the reason why Candace only wants to bring Linda to see it and not Lawrence.
  • The only times the boys don't come up with a big idea were in "The Best Lazy Day Ever", "Vanessassary Roughness", and "Candace Gets Busted".
  • The only times Candace didn't see the big idea were in "Hail Doofania!", "Atlantis", "Brain Drain", "Bullseye!", "Escape from Phineas Tower", "Buford Confidential", "Tri-State Treasure: Boot of Secrets", "Backyard Hodge Podge", "Where's Pinky?", "Thanks But No Thanks", "Live and Let Drive", "Father's Day" and "Imperfect Storm".