Free · No signup · Works in your browser
Write code.Hit run.No install.
Run C, C++, Java and Python in seconds, build web pages with a live HTML/CSS/JS preview, and practise SQL on a real database.
Works on any computer or phone with a browser — even the college lab.
Free for every student and developer.
def fees(months): return months * 1500 print("DCA fees:", fees(6))
$ DCA fees: 9000
Run
Finished in 0.04 s ✓
- 6
- languages and editors
- stdin
- program input supported
- Live
- HTML/CSS/JS preview
- 0
- installs or signups
The tool
Code online
C Compiler
Write and run C code online — free GCC compiler, no install.
C, C++, Java and Python run on a free public execution service. HTML/CSS/JS and SQL run entirely in your browser.
Privacy-first: your files are processed in your browser and never uploaded. The few tools that need a server — running C, C++, Java or Python code, reading a public web page, or a speed test — send only what you enter for that job.
Who it's for
Made for the people who actually use it.
Students
The pain
The lab PC has no compiler, installing Turbo C or a JDK at home is a headache, and practicals are next week.
The outcome
Write and run your C, C++, Java or Python program instantly — the same code works in the exam lab.
Web learners
The pain
Saving a file and refreshing the browser after every change makes learning HTML and CSS slow.
The outcome
Separate HTML, CSS and JS tabs with a preview that updates as you type.
Interview prep
The pain
You want to try a SQL query or a quick algorithm without setting up a database or IDE.
The outcome
A real SQLite database in the browser and compilers one click away.
- 01
Choose a language
C, C++, Java, Python, HTML/CSS/JS or SQL — each opens with a starter program.
- 02
Write your code
Edit the code and add program input (stdin) if it reads from the keyboard.
- 03
Run and see output
Click Run to see the output or errors, or watch the web preview update live.
Features
Everything you need.
Nothing you don't.
6 things it does well — and no settings page to get lost in.
C, C++, Java, Python
Compile and run real programs and see output and error messages.
Program input
Give input to scanf, cin, Scanner or input() before you run.
HTML / CSS / JS editor
Separate tabs with a live preview, fullscreen and download.
SQL practice
A real SQLite database running in your browser for queries and tables.
Starter programs
Each language opens with a working example you can edit or reset.
Works anywhere
Any modern browser on Windows, Mac, Chromebook or phone.
FAQ
Questions,
answered.
6 things people ask before they use the Online Compiler.
C, C++, Java and Python, plus an HTML/CSS/JavaScript editor with live preview and an SQL editor powered by SQLite.
Yes. Type the input into the stdin box before you click Run — it's passed to scanf, cin, Scanner or input().
HTML/CSS/JS and SQL run entirely in your browser. C, C++, Java and Python are sent to a compile service to run, and the output is shown here — don't include passwords or private data in your code.
Yes. Students use it to practise lab programs from the DCA, ADCA, BCA and B.Tech syllabus without installing anything.
No. Open the page, choose a language and start coding.
Yes. Acubens runs C, C++, Java, Python and web development courses at our Patna centre — see the courses page.
Question 01 of 06
Which languages can I run?
C, C++, Java and Python, plus an HTML/CSS/JavaScript editor with live preview and an SQL editor powered by SQLite.
Still have a question?
Our Patna team usually replies within the day.
Still stuck? Talk to us or message us on WhatsApp.
Keep going
21 more tools.
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