Computer science is the one field where a student in any country can compete on equal terms with a student in Palo Alto. The tooling is free, the judging is automatic, and nobody can see where you are sitting.
That makes it crowded, and it makes it confusing. Search "international computer science olympiad" and you will find results that charge you to enter sitting directly beside the competition that actually decides the world champion, which charges nothing and which you cannot apply to at all.
So this list is sorted by how you get in, which is the fastest way to tell those apart.
Olympiads your country selects you for
These are free, they are run by international bodies, and no amount of money gets you a place. Your route is your national olympiad.
International Olympiad in Informatics
The top of the sport, and one of the five international science olympiads. Pre-university students solve algorithmic problems across two competition days for gold, silver and bronze medals.
You cannot apply. Each country may send a team of up to four contestants, chosen through its own national olympiad in informatics, and national teams register through their country's IOI representative. In the United States that pipeline is USACO; in the Balkans it runs through the regional olympiad below.
The 2026 olympiad was held in Uzbekistan, Germany hosts IOI 2027, then Japan in 2028, Bulgaria in 2029 and Macau in 2030. Entry costs nothing, because selection is the price.
Balkan Olympiad in Informatics
The regional step that feeds the same pipeline, for high school students from Albania, Bosnia and Herzegovina, Bulgaria, Cyprus, Greece, North Macedonia, Moldova, Montenegro and neighbouring countries.
Free to enter, national selection again, and a realistic target a year or two before the IOI itself. If you are in this region, the national informatics olympiad is the only door worth knocking on.
International Olympiad in Artificial Intelligence
The newest of these, covering machine learning, natural language processing and computer vision, for students 20 or younger working toward a secondary school credential. National teams of four, selected through your country's National Olympiad in AI.
One difference from the IOI: there is a per-team registration fee covering accommodation, meals and local transport, which varied roughly between €1,550 and €3,700 for the 2026 edition depending on registration tier. Financial aid can waive it for a limited number of countries.
If your country has no National Olympiad in AI yet, the organisers run an initiative to help countries start one, which is worth an email from your school.
Competitions anyone can enter, free
No selection, no fee, no school required. This is where a student with a laptop and no local infrastructure should start.
Bebras
The largest computing competition in the world by a wide margin, and almost unknown outside the countries that run it well. In the most recent season Bebras recorded more than 4,283,427 participants from 78 countries.
It is a 45-minute online challenge of computational thinking puzzles rather than programming, so there is no language to learn first, and it runs for primary and secondary students at every age tier. You register through your country's national Bebras organiser, and it usually runs in November.
For a student with no coding background, this is the single easiest entry point into the field.
Apple Swift Student Challenge
Build an app playground in Swift and submit it. Judged on innovation, creativity, social impact and inclusivity, and the entry bar is unusually low for a competition with this name attached.
Free to enter, and open worldwide from age 13 in most countries, rising to 14, 15 or 16 in a specific list of them. You must be enrolled at an accredited institution, homeschool equivalent or STEM curriculum, or have graduated within the last 90 days, and you must not be employed full-time as a developer. Registration as an Apple developer is free.
Winners can take an award up to three times, and Distinguished Winners are invited to Apple in Cupertino for three days.
Battlecode
MIT's AI programming tournament, run every January. You write autonomous bots that fight in a live strategy game, so the discipline is strategy and algorithms rather than syntax.
Free, with more than $20,000 in prizes. Anyone worldwide can enter the Sprint Tournaments, and student teams, including non-MIT ones, are eligible for the remaining tournaments and prize money.
NASA International Space Apps Challenge
The largest annual global hackathon, built around Earth and space science data. Free, hybrid, and deliberately open: NASA's own wording welcomes anyone interested "no matter your age, skill level, or professional background."
The NASA name on a project is worth more on an application than the difficulty of the weekend suggests.
Global Appathon
Build a mobile app with MIT App Inventor to address a UN Sustainable Development Goal. Free, virtual, and open to all ages worldwide, with six categories: junior individual and team for under 13s, youth individual and team for 13 to 17, adult individual, and an all-ages team category of two to five members.
App Inventor is block-based, so this is a genuine option for students who have not written code before.
Global Hack Week
Major League Hacking's free monthly virtual hackathon series: themed week-long builds with live sessions, open to anyone 13 or older worldwide, with parental permission under 18.
Because it runs monthly rather than once a year, it is the best low-stakes way to start. Enter one, finish something small, and you have a project to talk about.
Competitions you pay to enter
These are open to anyone who registers and pays. That does not make them worthless, but it does mean the entry itself proves nothing, so judge them on what you would build and learn.
International Logic Olympiad
Propositional and relational logic for grades 6 to 12, organised by Luminas Inc. and, in the organisers' description, run in partnership with Stanford University, with the final round held on Stanford's campus.
$50 to enter, with a full fee waiver for households under $20,000 a year. Preliminary round at a regional testing centre in late April, with online testing for senior students without one nearby.
International Computer Science Olympiad
Run by the Science Olympiad Foundation for grades 1 to 10 across 72 countries, taken offline at your own school.
₹170 per student, collected by the school, so this is one of the cheapest competitions anywhere. The catch is the route: your school must be registered with SOF and individual students cannot enter, so it exists for you only if your school already takes part.
GENIUS Coding
Part of the GENIUS Olympiad in New York, for coding projects that address environmental problems. You need working Python and the ability to design algorithmic solutions, and you bring your own laptop to the in-person final.
$600 per participant, which makes it the most expensive entry on this page. Worth it only if the environmental framing genuinely matches your project.
How to tell a serious competition from a marketed one
Four checks, and they take about five minutes each.
- Who governs it? The IOI is one of five international science olympiads with a standing international committee. A competition run by a single private company is a different thing, whatever the name says.
- How do you get in? National selection means a country picked you. Paying to register means you picked yourself, which is what the admissions reader will understand too.
- Whose name is on it, and in what role? A campus can be hired. Look for whether the university runs the competition or simply hosts the final.
- What does it cost? The most prestigious competitions in this field, IOI and Bebras among them, cost nothing to enter.
Start your own journey
If you have never written code, start with Bebras in November or a Global Appathon build. Neither needs a programming language, both are free, and 4.2 million students a year do the first one.
If you can code and want a result that carries weight, find your country's national olympiad in informatics. That is the only route to the IOI, it takes more than one season, and it costs nothing but time.
If you want something on your application this term, Global Hack Week runs monthly, the Swift Student Challenge opens each winter, and Battlecode runs every January.
And keep the artefacts. The repository, the commits, the thing you built and what broke. In this field the work itself is checkable, which is exactly why it persuades.
Kai, the Borderless AI college counselor, works out which of these your age and country qualify you for, keeps the deadlines in one place, and helps you turn a project into something an admissions reader can follow. It's free to use.
Start with Kai, and read the stories from students who did it.
