Instant Costume Change

The Instant Costume Change is an ability of Superhero characters to change from their street clothes into their hero costumes, well, instantly. This doesn't include characters who wear their costumes under their normal clothing. The Instant Costume Change is usually accomplished by some bit of Applied Phlebotinum that automatically transforms the character's clothing with little action ? often a button push or just a thought.

Virtually all Henshin Heroes perform an Instant Costume Change when they transform into their powered modes. But other characters can have this ability as well. The exact mechanism by which the trope operates varies from character to character, but some common methods are include nanotechnology, morphable cloth, magic, and alien tech.

Examples of Instant Costume Change include:

Advertising

McDonalds commercial from 1991:

Narrator: How fast can Bugs Bunny change into Superbugs?
Bugs: Faster than you can say what's up -
(Beat as costume appears on him)
Bugs: - Doc!

Anime and Manga

In Magical Girl Lyrical Nanoha, mages summon their "barrier jackets" with their intelligent devices (or armed devices).
Many more examples at Henshin Hero.
In the Pokémon anime episode "The Light Fantastic" Jesse and James instantly change from their regular Team Rocket costumes into archeologists' garb.
- Heck, Jessie and James usually start out disguised as workers or sellers to lure Ash and the gang. And then, when the heroes are surrounded, they remove their disguise to show that they're actually Team Rocket. It doesn't make sense in some factors, though... for example, when they don't wear gloves in their disguise, but do wear them in their Team Rocket uniforms.
Science Ninja Team Gatchaman (AKA Battle of the Planets). G-Force had wrist band communications devices which also allowed them to change between their team uniforms and civilian clothing.
Cutie Honey has a special device built into her Boobs of Steel that allows her to instantly reconfigure her clothing and even her appearance; beyond the normal Henshin Hero effect, she can change into a number of alternate forms with unique skill sets, such as Biker Babe Hurricane Honey and Hot Scoop Scoop Honey.

Comic Books

A Green Lantern Ring can do this.
Spider-Man
- The Venom symbiont can alter its appearance to that of any clothing the host wants.
- During the Acts of Vengeance, Spidey had the powers of Captain Universe; one "trick" he used them for was conjuring up a costume out of thin air, built from molecules around him and restructured into cloth.
- The animated series Spider-Man Unlimited gave Peter Parker a wrist device containing nanomachines that rebuilt his street clothes into his Spidey suit.
In the Marvel Universe, Reed Richards invented an "unstable molecular fabric", which some characters can morph using their powers.
- This was done a lot in the X-Men animated series from the 1990s, by Storm and Phoenix.
The children from the comic Power Pack could change into their costumes by saying the words, "Costume on!"
The Wally West version of The Flash could create his costume from Speed Force.
- And any version of The Flash effectively pulls this one off just by being fast enough to change clothes in the blink of an eye.
- In addition to his speed, the Barry Allen version of the Flash was further aided by the use of a ring that stored a costume chemically treated so that it could be packed into the ring's compartment for this trope.
Subverted in modern Batman comics and film adaptations. Bruce's costume is too bulky to be worn under his regular clothes, so when an emergency pops up he has to travel to the Batcave(or somewhere where he has a spare costume in storage) to suit up.
The current classic universe version of Iron Man. His armor is now entirely part of his body and emerges from his bones when needed.
The members of Gen13 could do this for a period of time, thanks to high-technological bracelets. Grunge once grabbed Rainmaker's bracelet by mistake and didn't realize it until after he had used it to change costume.
Superman can fake it by virtue of super-speed, although the question of where his street clothes go often arises; it's generally been Handwaved away, with "explanations" such as "super-compressed and hidden in a pocket in his cape".
From The Mighty Thor; Thor or anyone with similar powers (such as Beta Ray Bill and Thunderstrike) can switch from costume to street clothes by slamming his hammer to the ground. In some cases, this activates the user's powers and/or disguises the hammer as a walking stick. This was lampshaded in one comic with Thunderstrike when he asks Spider-Man to talk over lunch, but has to switch to get money. He says he has no idea where his civilian clothes go, "but at least my wallet's safe."

Film

Undercover Brother. Undercover Brother jumps out of a window while dressed in what can be best described as a nerd disguise. On the other side, he comes out in his normal attire, complete with afro.
Buster Keaton did the same thing for real in Sherlock, Jr., entering the window in evening clothes, and emerging dressed as an old woman in a dress and shawl.
Jason in Mystery Team has shades of this.
Beautifully depicted in Superman II, when Clark goes into an alley and in a blur comes out as Superman.
Mr. Incredible had some kind of costume change device in his car in The Incredibles.

Live-Action TV

The Adam West Batman TV series had Batman and Robin changing into their costumes while sliding down the pole into the Batcave. They must have a heck of a contraption down there.
- Queen of Wands has a suggestion.
- In The Movie between the first and second seasons (think "shark repellent bat-spray") we see that there is a switch marked "Instant Costume Change Lever" that they pull on the way down.
Stargate SG-1 makes fun of their own tendency to skip over the scenes where SG-1 or other teams switch to combat uniform in the parody episode "200". When Walter is invited to join the team on a mission, he leaves from the control room dressed in a casual military uniform only to emerge from the nearby door seconds later dressed in standard SG team attire.
Shaktimaan, a famous Hindi serial from the 1990s deserves a mention. The superhero's alter-ego, Pandit Gangadhar Shastri could change into Shaktimaan (and back), simply by spinning around like a top.
Power Rangers has a few examples outside the usual morphing. All ninja-based characters are adept at Flung Clothing to completely change their wardrobe, and in Power Rangers Mystic Force, the unmorphed wizard robe uniforms appear when they enter the dimension their base is in. Another dimension gave them more medieval garb upon arrival.
On Star Trek: The Original Series, Sufficiently Advanced Aliens had a thing for putting female crewmembers into feminine clothing using their Stop Trick powers.
Wonder Woman could basically do this by twirling around a few times. In the first season or so, it was depicted as a slow-motion transition from one stage to another from military uniform to costume; in later seasons an optical effect of an explosion allowed them to do a more literally instant change.

Video Games

The superhero RPG Mutants and Masterminds has a feat called Quick Change, which allows a character to change between his street clothes and hero uniform as a free action.
Alex Mercer can switch between his Shapeshifter Default Form and his disguise form in about a second.
In Secret Agent Barbie, Barbie performs these when changing between Stealth, Action and Adventure modes, sometimes in broad daylight, in a public area, while surrounded by other people. This is never mentioned or explained.
Every character in Super Cosplay War Ultra has the ability to instantly change into different cosplay outfits, gaining the abilities of the character they're cosplaying.
By default every character in City of Heroes/City of Villains can do this, once they have two or more different costumes in their costume slots. Special effects for the costume change, though, have to be earned or found -- and make the change very much not instant.
Supergirl does this in pre-fight scenes in Injustice 2, appearing in the arena in street clothes and glasses, then zooming off-set and coming back a second later in costume.

Western Animation

Occurs frequently on The Magic School Bus. When the bus transforms, Ms. Frizzle and the kids' clothing will often change along with it. For example, if the bus turns into a submarine, everyone will instantly be wearing scuba gear.
Parodied in The Emperor's New Groove; villainess Yzma and her lackey Kronk reach her lab by riding down a Mayincatec roller-coaster that fits them into lab-coats and goggles en-route. When the heroes later sneak into the lab, they also get stuffed into the very ill-fitting costumes.
In the Justice League Unlimited episode "The Ties that Bind", Barda uses her Mega-Rod to swap her skimpy outfit for more modest and practical Powered Armor.