Harvard Computer Science course is available to everyone online — search for CS50 on YouTube or sign up for free at cs50.edx.org.

Harvard’s introductory course in Computer Science is available to everyone online — you can enroll for free at cs50.edx.org.

We’ve all been there. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

CS50’nin Türkiye’deki öğrencileri ve öğretmenleri kalbimiz sizinle Learn more, how to help at nytimes.com/2023/02/06/world….

Discover some final projects at the CS50 Fair at Yale University! You can enroll in CS50 for free at cs50.edx.org.

From @CS50’s entire team, happy holidays! 🎄We'll be back in 2025 with a new-and-improved CS50x, new opportunities to engage, updates to past courses, and some brand-new ones as well. There will also be a few surprises along the way! 🤫

Professor @davidjmalan on the difference between CS50x and CS50P.

Celebrate CS50 students' final projects with us! Even if you don't have any CS experience yet, you'll be able to create your own, too, by course's end. Take CS50 for free at cs50.edx.org.

Professor @davidjmalan on whether @cs50 helps you get a job.

Happy New Year from @CS50 🎄

Professor @davidjmalan explains whether you can work as a software engineer after @cs50.

😇 Search for CS50 on YouTube or enroll for free at cs50.edx.org.

It's a steep learning curve but worth the climb. Search for CS50 on YouTube or enroll at cs50.edx.org.

Professor @davidjmalan explains the difference between CS50 and CS50x.

This is CS50x 2024, now available on edX (cs50.edx.org) and YouTube (cs50.ly/youtube). Or search for “CS50” on Apple TV or Google TV.

Even Professor @davidjmalan sometimes writes buggy code. Learn how to write code and debug your own! Enroll for free at cs50.edx.org.

For @cs50’s students, teachers, and families in #Ukraine. npr.org/2022/02/25/108299294…

It’s challenging but definitely worth it. Search for CS50 on YouTube or enroll for free at edx.org/cs50.

Eclipse 2024 🦆 🟡

This is CS50x 2025, now available for free at cs50.edx.org and piped.video/cs50 as well as on Apple TV and Google TV. This year’s release includes new-and-improved lectures and problem sets, fun on-stage demos, and also more in-depth coverage of the more complex topics. Welcome aboard! 💡

Professor @davidjmalan and @cs50 have your back. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

It’s always a good time for a CS50 lecture. Search for CS50 on YouTube or sign up for free at cs50.edx.org.

Feels great. You can take CS50 for free at cs50.edx.org.

After CS50, you’ll never be the same again. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

Sometimes coding all night long is all you need. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

Week 0 of CS50 on Scratch will start in 15 minutes. Tune in live on @CS50’s X page! 🐈‍

More pictures from Week 0 of @CS50 Lectures 2024! 🐱

CS50 is about to start filming a brand-new course, an Introduction to Programming with R, led by CS50's own Carter Zenke, aka CS50R, whose lectures you are welcome to attend live via @Zoom or @YouTube! (The course itself will be freely available via @edXOnline on July 1, 2024, so attending live now offers a bit of a preview.) You can register to attend the live lectures at cs50.ly/live. Here's the course's description: "An introduction to programming using a language called R, a popular language for statistical computing and graphics in data science and other domains. Learn to use RStudio, a popular integrated development environment (IDE). Learn to represent real-world data with vectors, matrices, arrays, lists, and data frames. Filter data with conditions, via which you can analyze subsets of data. Apply functions and loops, via which you can manipulate and summarize data sets. Write functions to modularize code and raise exceptions when something goes wrong. Tidy data with R’s tidyverse and create colorful visualizations with R’s grammar of graphics. By course’s end, learn to package, test, and share R code for others to use. Assignments inspired by real-world data sets." You can also enroll (in advance) for the edX course itself at cs50.edx.org/r. #education #community #r

Some things are classic. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

.@CS50 is @Harvard University's free introduction to the intellectual enterprises of computer science and the art of #programming. ▶️ Watch on @YouTube at piped.video/cs50. Register via @edXOnline at cs50.edx.org. #education #community

Hello, world! @CS50's lectures in Sanders Theatre at @Harvard are open to the public, September 2025 – November 2025. Whether you are (or were!) a student or teacher of any of CS50's courses, or just CS50-curious, you are welcome to attend CS50's lectures in person in Cambridge, Massachusetts, USA. Fall 2025's lectures will become part of CS50x 2026 on @edXOnline. To attend in person, visit cs50.ly/attend. To watch online instead, register at cs50.ly/watch. SCHEDULE * Scratch on Wednesday, September 3, 2025 at 1:30 PM – 4:15 PM EDT * C on Monday, September 8, 2025 at 1:30 PM – 4:15 PM EDT * Arrays on Monday, September 15, 2025 at 1:30 PM – 4:15 PM EDT * Algorithms on Monday, September 22, 2025 at 1:30 PM – 4:15 PM EDT * Memory on Monday, September 29, 2025 at 1:30 PM – 4:15 PM EDT * Data Structures on Monday, October 6, 2025 at 1:30 PM – 4:15 PM EDT * Python on Wednesday, October 8, 2025 at 1:30 PM – 4:15 PM EDT * SQL on Monday, October 20, 2025 at 1:30 PM – 4:15 PM EDT * Artificial Intelligence on Friday, October 24, 2025, at 12:00 PM – 1:00 PM EDT * HTML, CSS, and JavaScript on Monday, November 3, 2025 at 1:30 PM – 4:15 PM EST * Flask on Monday, November 10, 2025 at 1:30 PM – 4:15 PM EST * The End on Monday, November 17, 2025 at 1:30 PM – 4:15 PM EST

It’ll all make sense. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

This is @CS50's Introduction to Databases with SQL, with CS50's own Carter Zenke. Available for credit at @HarvardExt starting September 5, 2023, at web.dce.harvard.edu/extensio…. Available on @edXOnline starting October 1, 2023, at cs50.edx.org/sql.

Too good to be true, right? But it's true! Search for CS50 on YouTube or enroll for free at cs50.edx.org.

This is CS50x 2023, @Harvard's introduction to the intellectual enterprises of computer science and the art of #programming with @davidjmalan, in 4K HDR. Starts January 1 on @edXOnline. Register for free at cs50.edx.org. Subscribe to @CS50 at piped.video/cs50.

Week 1 of CS50 on C will start in 15 minutes. 🎬 Tune in live on @CS50’s X page!

Available as of today (for free) on @edXOnline, @CS50's Introduction to Artificial Intelligence with #Python, with CS50's own @brianyu28, at cs50.edx.org/ai!

CS50R Lecture 1 is about to start! Join us live and enjoy! ✨ piped.video/live/77cqSOzMoys…

Brian’s Birthday at @CS50’s favorite Changsho! 🎂

What a satisfying feeling. Enroll for free at cs50.edx.org or search for CS50 on YouTube.

You got this. Enroll for free at cs50.edx.org or search for CS50 on YouTube.

This is @CS50's (free) Introduction to Artificial Intelligence with Python, with CS50's own @brianyu28, at cs50.harvard.edu/ai. Starts 1 April 2020. Also on edX at cs50.edx.org/ai.

Trust us, you’ll feel great, too. Enroll for free at cs50.edx.org or search for CS50 on YouTube.

Professor @davidjmalan has always got your back. Search for CS50 on YouTube or enroll at cs50.edx.org.

Professor @davidjmalan on whether it makes sense to take CS50P after CS50x and CS50W.

Live from @Harvard University on Thursday, April 25, 2024 at 1:30 PM – 3:30 PM EDT, a @CS50 workshop on artificial intelligence (AI) via @Zoom and @YouTube. Open to all. Register at cs50.ly/register. A workshop in two parts for CS50x students, teachers, and alumni. First, a look at how CS50 has incorporated artificial intelligence (AI), including its new-and-improved rubber duck debugger, and how it has impacted the course already. 🦆 Then, a hands-on introduction to implementing your own AI-based chatbot using @OpenAI's APIs, maybe a duck or even a cat! "In Summer 2023, we developed and integrated a suite of AI-based software tools into CS50 at Harvard University. These tools were initially available to approximately 70 summer students, then to thousands of students online, and finally to several hundred on campus during Fall 2023. Per the course's own policy, we encouraged students to use these course-specific tools and limited the use of commercial AI software such as ChatGPT, GitHub Copilot, and the new Bing. Our goal was to approximate a 1:1 teacher-to-student ratio through software, thereby equipping students with a pedagogically-minded subject-matter expert by their side at all times, designed to guide students toward solutions rather than offer them outright. The tools were received positively by students, who noted that they felt like they had 'a personal tutor.' Our findings suggest that integrating AI thoughtfully into educational settings enhances the learning experience by providing continuous, customized support and enabling human educators to address more complex pedagogical issues. In this paper, we detail how AI tools have augmented teaching and learning in CS50, specifically in explaining code snippets, improving code style, and accurately responding to curricular and administrative queries on the course's discussion forum. Additionally, we present our methodological approach, implementation details, and guidance for those considering using these tools or AI generally in education." Recording will be available on demand afterward. #education #community #ai #duck

This was the very first lecture of CS50 in 1996, when Professor @davidjmalan himself took the course! Taught in @harvard University's Science Center at the time by the legendary computer scientist and programmer Brian Kernighan, who wrote the world's very first "hello, world" program. Professor Kernighan coined the name "UNIX," contributed to the operating system itself, and is the "K" in K&R, a famous book on C. Today, you can enroll in CS50x 2024 for free at cs50.edx.org. Link also in @cs50's bio.

"Computer Scientist Answers Computer Questions From Twitter," with @davidjmalan on @WIRED piped.video/watch?v=QUNrBEhv…

"On the occasion of this year's Dies Academicus at @Leuphana University Lüneburg, @Harvard professor @davidjmalan has been awarded an honorary doctorate by the Faculty of Management and Technology..." leuphana.de//en/university/e…

Catch the Cybersecurity live streams on CS50’s YouTube, Instagram, and TikTok, or sign up to participate live at cs50.ly/live.

10 years apart, these CS50 Fairs brought students together to share their final projects with classmates. Search for CS50 on YouTube.

Sometimes one class is all it takes. Enroll for free at cs50.edx.org or search for CS50 on YouTube.

You could always enroll in other CS50 courses too… At edx.org/cs50.

This is the second cohort of (nearly 300) teachers in Indonesia who took CS50x over the past several months in preparation for teaching CS in their own classrooms, after which everyone convened in Jakarta for a workshop led by Prof. @davidjmalan and team, in collaboration with Minister @nadiemmakarim of Indonesia's Ministry of Education, Culture, Research, and Technology. 🇮🇩 To adopt or adapt @CS50 in your own school, community, or organization, email outreach@cs50.harvard.edu. #education #community

This is @CS50's Introduction to Cybersecurity, with Professor @davidjmalan. Available for credit at Harvard Extension School starting September 5, 2023, at web.dce.harvard.edu/extensio…. Available on edX starting October 1, 2023, at cs50.edx.org/cybersecurity.

Search for the new-and-improved CS50x 2024 on YouTube or enroll for free anytime at cs50.edx.org.

CS50x Puzzle Day is an online adaptation of an event we hold at Harvard each year, an opportunity to collaborate on a team with classmates, family, friends, students, and colleagues on a packet of puzzles (i.e., logic problems). The event is open to everyone around the world, whether taking @CS50 or not. No prior CS experience required. Teams of size 2, 3, or 4 are encouraged, or you can participate on your own. Teachers are welcome to host their own version during class. Starts anytime after 00:00 on Friday, April 5, 2024, in your own time zone. Ends anytime before 23:59 on Monday, April 8, 2024, in your own time zone. Register officially at cs50.ly/register anytime before 23:59 on Monday, April 8, 2024, in your own time zone. Every member of your team should register individually by submitting the form as well. See cs50.medium.com/this-was-cs5… for a summary of last year’s CS50x Puzzle Day as well as some past puzzles for practice. Indeed, the best way to practice for this year is to solve past puzzles first!

This is CS50x 2020, including new-and-improved #lectures, new problem sets, choice of tracks, and free @cs50 #certificates, cs50.harvard.edu/x/2020/. Verified certificates available at cs50.edx.org/. Transferrable course credit available at extension.harvard.edu/course….

As a part of a global campaign to make people more aware of computer science education, @CS50 has installed a few (huge!) rubber duck debuggers in some of the world's biggest cities. Comment if there’s one in your city! 🦆

This is David J. Muppet. "Draw this in the style of Muppets," a prompt to @OpenAI's GPT‑4o model.

قلوبنا مع طلاب و اساتذة CS50 فى سوريا Learn more, how to help at nytimes.com/2023/02/06/world….

I’m sorry, how? Take CS50 at cs50.edx.org.

Enroll into any of CS50’s courses for free at edx.org/cs50 or search for CS50 on YouTube. Links also in @cs50’s bio.

After all, you don’t need any programming experience to take CS50. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

CS50 Lecture on Artificial Intelligence (AI) is starting now. Tune in live on @CS50’s X page! 🤖 nitter.app/i/broadcasts/1vAGROgOp…

Week 5 of CS50 on Data Structures will start in 15 minutes. Tune in live on @CS50’s X page! 🌳 nitter.app/i/broadcasts/1ynKODkLQ…

More photos from the @CS50 Fair 2023 at @Harvard!

Check out some photos from this year’s lectures 📸

Professor @davidjmalan and @CS50’s own @coltonTogden answer viewers’ questions, discussing recent developments in AI, working in the real world, and much more.

Join CS50's channel on Telegram for lectures, Q&As, quizzes, and more at t.me/cs50x.

From @Harvard University in Cambridge, Massachusetts, this is CS50x 2025. Available on January 1, 2025, on YouTube, edX, Apple TV, Google TV, and beyond. Open to anyone online; no prior programming experience required. Enroll for free at cs50.edx.org. And meet @CS50’s #AI-powered duck of whom you can ask questions along the way, thanks to GitHub, OpenAI, and Microsoft! 🦆

You're invited... @CS50's lectures in Sanders Theatre at @Harvard University are open to the public, September 2024 – November 2024. Whether you are (or were!) a CS50x student, a CS50 AP student, a prospective student, a teacher, a parent, or a Harvard or alum (or anyone else!), you are welcome to attend CS50's lectures in person in Cambridge, Massachusetts, USA. Fall 2024's lectures will become part of CS50x 2025 on @edxOnline. To attend in person, register at cs50.ly/attend. To watch online, register it cs50.ly/watch. #education #community

First-ever "hello, world" by Brian Kernighan of @Princeton (who taught @CS50 when @davidjmalan took it at @Harvard).

An in-person @CS50 lecture in Seattle, Washington, USA on Monday, March 25, 2024, for CS50x students, teachers, and alumni, hosted by the Harvard Club of Seattle at @seattleu. (Afraid the event will not be filmed!) Open to anyone in the Seattle area; please feel welcome to share. Register at eventbrite.com/e/using-ai-as…. "Please join us for an engaging, interactive, and entertaining discussion about how Prof. Malan and his team have created and are using AI as a personal tutor for his students. Prof. @davidjmalan teaches CS50, which has more than 600 in-person students at @Harvard, more than 200 in-person students at @Yale, and more than 5.6 million registrants on @edXonline." #education #community

Join us for a Q&A with Professor @davidjmalan and @CS50’s own Yuliia Zhukovets this Friday, May 16, at 11:30 AM EDT on CS50’s YouTube. Comment with your most pressing questions below! 👇

As we like to say… Demanding, but definitely doable. See for yourself by searching for CS50 on YouTube or enrolling for free at cs50.edx.org.

Week 3 of CS50 on Algorithms is about to start. 📊 Tune in live on @CS50’s X page! nitter.app/i/broadcasts/1BRKjwjZA…

Some behind-the-scenes photos from @CS50's production team! 🎬

Week 2 of CS50 on Arrays is about to start. 📟 Tune in live on @CS50’s X page! nitter.app/i/broadcasts/1djGXrkoq…

This was @CS50 at @Yale, 2015 – 2024. 💙 cs50.yale.edu/

This is what Professor @davidjmalan must feel like.

Happy first day of spring from @CS50! 🌻

More photos from the CS50x Indonesia Workshop 2024!

Now available on @AppleTV devices, a @CS50 app, with CS50's courses, live streams, podcast, puppetry, short films, music videos, and more. Latest videos in 4K HDR. Search for "cs50" on an @AppleTV device to install. Apps for other devices coming soon. piped.video/nmFwUi6J3oM

Now built into @CS50 IDE, rubber duck debugging! cs50.noticeable.io/posts/rub…

Week 1 of @CS50's live lectures at Harvard this semester (which will become part of CS50x 2025 on January 1.) 🔴 Did you catch it live?

Even CS50 Professor David J. Malan has to admit… CS50’s AI-powered rubber duck is a lifesaver. Try for yourself at cs50.ai. 🦆

Here are some @CS50 memories from more than a decade ago! 😱

"@CS50, however, remains the largest class with corporate sponsorships. The popular introductory computer science class lists companies such as @Meta, @awscloud, @Google, @Microsoft, @OpenAI, [and] @GitHub [...] as its partners... "Julia J. Poulson '26, a former CS50 student, said that she found the partnerships helpful. 'I actually think they used it in a very good way that made the class really accessible to people,' she said, referring to VS @Code. "'Typically, I’ve reached out to alumni or others in industry when we’ve caught a glimpse of some technology that we think could improve students’ or TFs’ experience in CS50,' @davidjmalan wrote. 'These collaborations enable CS50’s students or TFs and CAs to learn and leverage technology that we might not otherwise have access to,' he added." thecrimson.com/article/2025/…

Training wheels off! Search for CS50 on YouTube or enroll for free at cs50.edx.org.

Does this happen to you? Watch the phone book episode in full—just search for CS50 Lecture 0 on YouTube.

You’re in for a ride. Search for CS50 on YouTube or enroll for free at cs50.edx.org.

Computer Science is in the air. Enroll for free in @Harvard's @CS50 with @davidjmalan at cs50.edx.org. Subscribe at piped.video/cs50. piped.video/shorts/JgejyS-lS… #education #community

Birthday photos of @CS50’s own Carter Zenke! 🎉

Here’s the live stream from the @CS50 Fair 2023 at @Yale with some of the students’ final projects! piped.video/Jn5tvbA3E4w?si=LXUp…

Dreams come true. CS50 lectures are open to the public. Sign up at cs50.ly/attend.

This is @CS50 for Lawyers with @davidjmalan and @DLloyd09. cs50.harvard.edu/law/