OnlineGDB alternative
What is a good OnlineGDB alternative?
OnlineCompiler.io is a free alternative if you want to run code in 46 languages with no ads, share it by link, or build the same thing into your own site. It has no debugger and its browser editor runs one file, so stay with OnlineGDB if you need to step through code or run a project of several files.
By the OnlineCompiler.io team. Updated . We make OnlineCompiler.io, so we're one of the options here. Every competitor figure links to the vendor's own page, and we say where our API falls short.
What does OnlineGDB do well?
By its own pages (read 6 Nov 2026), OnlineGDB is a compiler and debugger in the browser. It does several things we do not:
- A debugger. The home page has a Debug button and a panel with continue, step over, step into and step out, a call stack, local variables, watch expressions and breakpoints. Its FAQ says C and C++ use gdb. It lists pdb for Python 3, but also says debugging Python is not yet supported.
- Projects with several files. OnlineGDB announced multifile projects in June 2017: you add files to a project and run them together. A community answer from May 2025 says an Upload File button lets your program read files you upload (OnlineGDB Q&A). The FAQ gives the size limits: 100 KB per file and 200 KB per project.
- Saved projects and sign-in. It has My Projects, and sign-in with Google, Facebook or GitHub. Its Share Link dialog can keep a copy forever for a logged-in user.
- A long interactive session. The FAQ says a console run can last until the program ends or 15 minutes of inactivity, while a text-mode run gets 10 seconds and 256 MB.
- A Classroom section. The home page links to one. Its page did not describe it when we looked, so we say nothing more about it.
The home page shows a Remove Ads link. If you debug C or C++ programs, or your course sets projects of several files, OnlineGDB is the better fit.
How is OnlineCompiler.io different?
- No ads. Open the online compiler, pick a language, press Run. Type input in the Input tab first, if the program reads any.
- 46 languages, each at a stated version, each with its own page, such as the Python, Java and C++ online compilers.
- Share links kept 90 days with no account. A link to your code that anyone can open and run (OnlineGDB's copies last up to a month without one). Save keeps code in a free account.
- Check your output against test cases. The online compiler with test cases runs a program against several inputs and marks each passed or failed.
- Stated limits per run. OnlineGDB's FAQ gives 10 seconds and 256 MB for text mode, and its console mode runs until 15 minutes of inactivity. A run here can last 30 seconds with 512 MB of memory and 2 CPUs, and has no network access.
- An API and a widget for your own site. If you are a teacher or a developer, you can run the same languages from your app through the API, or put an editor in your pages with the embeddable code editor. Through the API a program can come with extra source files (several source files), so a header and its .cpp file or several Java classes run together. The guides header files in an online C++ compiler and a Java program with several classes show it with real output.
OnlineGDB and OnlineCompiler.io side by side
OnlineGDB's column is what its own pages say on 6 Nov 2026; ours is what this site does today.
| You want | OnlineGDB | OnlineCompiler.io |
|---|---|---|
| A debugger with breakpoints and stepping | Yes for C and C++ (gdb) | No |
| A project of several files in the browser | Yes | No. The editor runs one file; the API takes several |
| Uploading a data file for the program to read | Yes, per a 2025 community answer | Through the API, not in the browser editor |
| Run with no account | Yes; shared copies last up to a month without a login, Keep Forever needs one | Yes; share links last 90 days |
| No ads | Shows a Remove Ads link | No ads |
| Languages | Over 40 entries in the language menu | 46, each at a stated version |
| Time and memory per run | 10 seconds and 256 MB in text mode; longer in the console | Up to 30 seconds and 512 MB, no network |
| Test cases with pass or fail | Not on the pages we read | Yes, on the test cases page |
| Run code from your own site or app | Share and Embed codes for a program | Yes: API and widget, free up to 100,000 runs a month |
Who should stay with OnlineGDB?
- Students learning C or C++ who need to step through code and watch variables.
- Courses whose exercises are projects of several files that students edit together in the browser.
- People who want projects saved in an account and one editor for everything, and do not mind ads.
Who should use OnlineCompiler.io?
- Students who want to run a program now, in any of 46 languages, with no ads.
- Teachers who want to hand out a share link, or check answers against test cases.
- Developers and course builders who want runnable code inside their own site, or several source files through an API.
For a class that puts the widget in its own page, a free widget key takes 30 runs a minute and 8 waiting at once across all your students. A class pressing Run in the same moment can go over that; those students see a message and can press Run again a few seconds later. The pricing page lists the paid plans' limits.
You can also use both: OnlineGDB to debug, and this to run and share.
Frequently asked questions
Is there an online debugger like OnlineGDB here?
No. OnlineGDB has a Debug button with breakpoints and step controls for C and C++. OnlineCompiler.io has no debugger: you run the whole program and read its output and errors. For stepping through code, use OnlineGDB.
Do I need an account to run code?
No. You can write, run and share code with no sign-in, and the editor shows no ads. An account is only needed for Save. Share links made without an account last 90 days. OnlineGDB's home page runs code without a login too, and its shared copies last up to a month without one.
Can I run a project with several files?
Not in the browser editor, which runs one file. Through the API you can send a program with extra source files, such as a C++ header and its .cpp file, or several Java classes. The guides show how, with real output.
Which languages does it run?
46 languages, from Python, Java, C and C++ to Rust, Go and SQL. Each has its own page at its current version, listed on the online compiler page.
Is it free for a class?
Running code in the browser is free with no account. If you put the editor in your own site with the widget, the free plan includes 100,000 runs a month for all your students together, with no credit card. The limits are per account: on the free plan, a widget key takes 30 runs a minute and 8 waiting at once across all your students. A class pressing Run in the same moment can go over that; those students see a message and can press Run again a few seconds later. The pricing page lists the paid plans' limits.