If you ask a room full of historians when was the first computer created, you’re going to get a headache. Honestly, it’s a trap. Most people want a single date—a "Eureka!" moment where a guy in a bowtie flipped a switch and a screen flickered to life. But history is rarely that clean. Depending on how you define "computer," you could be looking at a device from 1945, 1837, or even two thousand years ago.
It’s complicated.
Most of us think of a computer as a glowing rectangle we use to argue with strangers on the internet. If that’s your definition, then the first computer didn't show up until the mid-20th century. But if you mean a machine that calculates complex data without a human brain doing the heavy lifting, we have to go back way further.
The story is less about a single invention and more about a slow, agonizing crawl toward automation.
The Victorian Fever Dream of Charles Babbage
Let’s start in 1837. This is where most academic types point when they talk about the conceptual birth of computing. Charles Babbage, a brilliant and notoriously grumpy English mathematician, drafted plans for the Analytical Engine.
✨ Don't miss: Why Pictures of Engines in Cars Look So Different Today (And What to Actually Look For)
He didn't just want a calculator. He wanted a monster.
Babbage envisioned a massive, brass, steam-powered machine that used punch cards—an idea he borrowed from Jacquard looms used in the textile industry. It had a "mill" (a CPU) and a "store" (memory). It could even make decisions based on its own results, which we now call conditional branching.
Technically, this was it. This was the first general-purpose computer.
Except for one small problem: it was never actually built. Babbage was a perfectionist who constantly tinkered with his designs, and the British government eventually got tired of throwing money into a brass-shaped hole. If you’re asking when was the first computer created in terms of a physical, working machine, Babbage doesn't quite take the trophy, even though his friend Ada Lovelace wrote what is considered the first computer program for it. She saw that the machine could do more than just crunch numbers; she thought it might one day create music or art. She was a visionary. Babbage was just a guy who wanted a very big calculator.
The Antikythera Mechanism: A 2,000-Year-Old Surprise
We should probably talk about the sponge divers. In 1901, divers off the coast of the Greek island Antikythera found a lump of corroded bronze in a Roman-era shipwreck. For decades, nobody knew what it was.
It turned out to be an analog computer.
Built sometime between 150 BC and 100 BC, the Antikythera Mechanism used dozens of intricate bronze gears to track the cycles of the solar system, predict eclipses, and even time the Olympic Games. It’s terrifyingly advanced. There is nothing else like it in the historical record for another thousand years. While it wasn't programmable in the modern sense—you couldn't tell it to play Solitaire—it performed complex calculations based on user input (turning a crank).
It proves that the urge to automate thought is ancient.
The World War II Explosion: Z3 and Colossus
The real pressure cooker for computing was, unsurprisingly, total war. The 1940s were a chaotic sprint.
In 1941, a German engineer named Konrad Zuse finished the Z3. It was the first working, programmable, fully automatic digital computer. It used 2,300 relays. It worked. But because it happened in Nazi Germany during the height of the war, its impact on the global evolution of tech was stunted. The original machine was actually destroyed during an Allied bombing raid on Berlin in 1943.
Meanwhile, at Bletchley Park in England, Tommy Flowers was building Colossus.
This machine was designed specifically to crack the "Tunny" code used by the German High Command. It was the first electronic, digital, programmable computer. It used vacuum tubes instead of slow mechanical relays. It was a beast. But because it was a military secret, the world didn't even know it existed until the 1970s. Thousands of people worked on these machines and then went home and told no one, which is wild to think about.
ENIAC and the Dawn of the Modern Era
If you’re looking for the "celebrity" of early computers, it’s ENIAC (Electronic Numerical Integrator and Computer).
Unveiled in 1946 at the University of Pennsylvania, ENIAC was the first "Turing-complete" electronic computer that could be reprogrammed to solve a vast range of numerical problems. It was built by John Mauchly and J. Presper Eckert.
It was massive.
It weighed 30 tons.
It took up 1,800 square feet.
It used about 18,000 vacuum tubes.
When it turned on, legend has it the lights in Philadelphia dimmed. ENIAC was a turning point because it was public, it was fast, and it showed the world that electronic computing was the future. However, it didn't have "stored programs." To change what the machine was doing, you had to physically rewire it using cables and switches. Imagine having to open up your laptop and move wires around just to switch from Word to Excel.
The first computer to actually store a program in its own memory was the Manchester Baby in 1948. That’s when the "brain" of the computer finally started to look like what we use today.
Why Does This Timeline Keep Shifting?
The reason you see different answers to "when was the first computer created" is that the goalposts move based on who you're talking to.
- The "Idea" School: Points to 1837 (Babbage).
- The "Analog" School: Points to 100 BC (Antikythera).
- The "Digital" School: Points to 1941 (Zuse).
- The "Electronic" School: Points to 1943 (Colossus).
- The "Commercial" School: Points to 1951 (UNIVAC I).
UNIVAC I is important because it was the first computer sold to a business (the U.S. Census Bureau). Before UNIVAC, computers were one-off experiments or military secrets. UNIVAC turned computing into an industry. It famously predicted the 1952 presidential election results on TV, which absolutely blew people's minds.
The Transistor: The Moment Everything Actually Changed
We can't talk about when the first computer was created without mentioning 1947. That’s the year William Shockley, John Bardeen, and Walter Brattain at Bell Labs invented the transistor.
Before the transistor, computers used vacuum tubes. Vacuum tubes were hot, they burned out constantly, and they attracted moths (which is where we get the term "debugging"—Grace Hopper once literally found a moth in a relay).
The transistor replaced the tube. It was small, reliable, and efficient. Without it, your "computer" would still be the size of a refrigerator and require its own cooling plant. The first fully transistorized computer, the TRADIC, was built in 1954. That’s the real ancestor of the smartphone in your pocket.
Common Misconceptions About Early Computers
People often think the first computer was built by IBM or Apple. Not even close. IBM was around, but they were making punch-card tabulators for businesses. Apple didn't show up until 1976.
Another big mistake is thinking the first computer had a screen. It didn't. Early computers spat out paper tape or punched cards. You didn't "see" the result; you read it off a printout. The idea of a "monitor" didn't really take hold until the 1950s and 60s with projects like the Whirlwind at MIT, which used a CRT (Cathode Ray Tube) to show real-time data.
Insights for the Curious
If you’re trying to wrap your head around this history, don't look for a single date. Look for the transition of power.
- Human to Mechanical: We stopped using our fingers and started using gears.
- Mechanical to Electronic: We stopped using gears and started using electricity.
- Fixed to Programmable: We stopped building machines that did one thing and started building machines that could do anything.
If you want to see this history in the flesh, you should visit the Computer History Museum in Mountain View, California, or the Science Museum in London. Seeing the scale of ENIAC or the intricate brass of a Babbage reconstruction puts things in perspective. It makes you realize that our current tech didn't just appear; it was built by thousands of people who were mostly just trying to solve very specific, very annoying math problems.
How to Dig Deeper into Computing History
- Visit Bletchley Park: If you're ever in the UK, go see where Colossus lived. It’s the birthplace of the information age.
- Read "The Innovators" by Walter Isaacson: It’s a great breakdown of how collaboration, rather than lone geniuses, built the computer.
- Check out the "Manchester Baby" replica: Research the Small-Scale Experimental Machine (SSEM) to see the first time a computer "remembered" a task.
- Research the 1973 Patent Lawsuit: Look up Honeywell v. Sperry Rand. A judge actually ruled that the ENIAC patent was invalid and that the basic ideas of the electronic computer were derived from a guy named John Vincent Atanasoff. This is a huge, often overlooked part of the "who was first" debate.
The reality is that "the first computer" is a title shared by many. Babbage had the dream, Zuse had the hardware, and the team at ENIAC had the scale. We’re just living in the aftermath of their collective obsession.