Mecha Anime is all about the wild fun that the creators make for fans, and it requires quite a bit of tuning one's mind down. With this science-fiction subgenre, the emphasis is on the word "fiction." From the robots' abilities to magical connections to teenagers more often than adults, mecha anime is all about the wild fun of how crazy the robots are.

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There's also quite a bit of a size competition between giant robots. Although the size is never specified within the Anime, every giant robot is not as big as fans think, with some only towering over humans and others somehow greater than the Milky Way itself.

10 Code Geass: The Knightmare Frames Are Only Fearsome To Tiny Human Beings (4-5 Meters)

Lelouch from Code Geass

The power struggle in Code Geass is fought on the battlefield by pilots of large robots called Knightmare Frames. These robots have the firepower of guns, lances, and whatever the scientists think of next. Some of them can even fly, but as frighteningly powerful as these robots are, their size pales in comparison to most giant mecha.

Rising to only about 4-5 meters tall, a Knightmare frame could easily be stepped on accidentally by one of the anime larger robots with how small it is in comparison.

9 Gundam: The Nu Gundam Fares Well In Battle, But Not In Size (23 Meters)

Nu Gundam

Its official name is RX-93, but Gundam fans will recognize this robot as the Nu Gundam. As the strongest Gundam of its time, the Nu Gundam is the driving force of the Neo Zeon army. Equipped with a powerful Vulcan gun, beam saber, and rifle – as well as a shield and a beam machine gun – the Nu Gundam is a feared sight for enemy eyes, standing at 23 meters tall (0.023km).

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This robot's ability to strike fear would wear off, however, if it stood beside many other giant robots. The Nu Gundam is a force to be reckoned with for sure, but not at the tallest height of giant mecha.

8 Gundam: The Devil Gundam Is Huge Even Without Its Special Ability (24 Meters)

Devil Gundam

One of the most fearsome Gundams throughout the franchise, the Devil Gundam is a terrifying mech not just in name, but its capabilities. The Devil Gundam combines technological and organic science, proving to be an overwhelming challenge for the heroes. Although this Gundam had the standard weapons that every Gundam had, the Devil Gundam relied more on its fighting strength along with its ability to heal itself from any damage.

The Devil Gundam also has the ability to make its body larger by merging with other materials. It wound up becoming as large as planet Earth in the anime, but at its base size it stands at 24 meters tall.

7 Neon Genesis Evangelion: Unit-01 Towers The Tallest Buildings In Japan (40 Meters)

EVA Unit-01

Even more fearsome than the Nu Gundam is Unit-01 EVA from Evangelion, which has the power to destroy celestial monsters. The Evangelions are, in fact, monsters themselves with their own supernatural strengths. Each of them towers above buildings, acting as the only hope left for humanity.

Standing approximately 40 meters tall (0.040 kilometers), Unit-01 is piloted by the main hero Shinji, and thus is at the center of the story. Infamous for its and strength and terror throughout the series, Unit-01 is still not the tallest of the bunch.

6 Voltron: The Legendary Defender Is As Tall As Big Ben (100 Meters)

The Paladins Stand Before Voltron

Voltron, from the series Legendary Defender, is an even greater symbol of hope than any of the Transformers, but that happens when one is popular across the galaxy. The name "legendary defender" is not just there for show, as Voltron is fated to protect the universe from evil.

At 100 meters tall. (0.1 kilometers), Voltron is capable of swift space travel and equipped with a variety of powerful weapons all strengthened with the cosmic energy of quintessence. The power of quintessence along with the strong bond between paladins and robot lions are what form the giant protector of the universe.

5 Darling In The Franxx: Strelitzia Is Tall Enough To Ride With The Big Robots (332 Km)

Darling in the FranXX Main Cast Stands Before Strelizia Mecha

The giant mechs from Darling In The Franxx never fly through space, but they are large and in charge on the battlefield. Strelitzia, arguably the strongest of the giant robots, is piloted by the hotblooded Zero Two and tenacious Hiro, who turn the tide in the war against the Klaxosaurs.

Strelizia's height towers above the main character's home, the plantation, standing at 332,000 meters (332 km). Though its outer appearance may look unassuming, Strelitzia is a giant force to be reckoned with, making the oversized robot a perfect example of what a giant mecha is.

4 Top Wo Nerae 2! Diebuster: The Humanoid Defender Of Earth Towers The Legendary Defender (10,000 Km)

Diebuster

Another robot destined to protect humanity, Diebuster appears in the series Top Wo Nerae 2! Diebuster, otherwise known as Gunbuster 2. In Gunbuster 2, Diebuster is actually a human girl named Nono who can transform into a mega robot. She uses her supernatural abilities and strengths to fight monsters hellbent on ending the human race. While a strange concept to grasp, Diebuster still fits into the mecha robot category, standing at an impressive 10,000 km tall..

3 Getter Robo: The Emperor Is Called So For A Big Reason (12,000,000,000 Km)

Getter Robo's Final Form Emperor

The Getter Robo can be called the grandfather of all combining mechas, as it was the first to put out the concept back in 1974 when the series first aired. It also happens to be one of the first to have teen pilots operating the mech. The anime features robots that have the ability to evolve in strength and in size, with the final form being the Getter Emperor.

As the strongest and largest of all Getter forms, the Getter Emperor is 12,000,000,000 km tall. The size has a lot to do with its ability to absorb just about anything in the universe, but it's still an incredible feat nonetheless.

2 Tengen Toppa Gurren Lagann: Measuring This Robot Requires A Journey Through The Galaxy (10 Million Light Years)

Tengen Toppa Gurren Lagann

Echoing the novel ideas of Getter RoboTengen Toppa Gurren Lagann is all about evolving and growing robots, and blows the concept up to the point of massive ridiculousness in the best way. Starting out as one of the smallest robots, Lagann, piloted by the main character Simon, has the ability to combine with any robot no matter the size. More than the ability to combine, Gurren Lagann also evolves, growing beyond the size of Earth itself.

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In the fight against the alien race the Spirals, the heroes venture into space, eventually surviving to fight one final battle of astronomical levels. The already giant robot Gurren Lagann grows yet again to become Tengen Toppa Gurren Lagann, which is 10 million light years tall, and big enough to start hurling galaxies at the enemy. Surprisingly enough, this is not the biggest mech of all time.

1 Tengen Toppa Gurren Lagann Movie 2: Super Tengen Toppa Gurren Lagann (150 Million Light Years)

The Super Gurren Lagann Towers Over Reality

In an anime where the main characters are constantly evolving to higher levels through sheer willpower, it makes sense that the only mech that could beat Tengen Toppa Gurren Lagann is another from the same series. In the second recap film, the heroes fly into space to defeat the Spirals and protect humanity from extinction.

In the alternative version of the final battle, Tengen Toppa Gurren Lagann transforms into a super version of itself, which appears to be spiral energy taking the shape of the beloved character Kamina. Super TTGL is God-like in appearance and in size, rising to 150 trillion light-years, and making it the biggest Anime Mech of all time.

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