Open source means a company publishes its software’s underlying code. Anyone, including independent security researchers, can read it, check it, and confirm it does what the company says. This does not automatically make a service more private or secure. But it does make claims checkable rather than a matter of trust alone. Closed-source software asks you to take the company’s word for it. Open source lets you, or someone you trust, verify it.
Frequently asked questions
What does open source mean?
Open source means a company publishes the actual code behind its software. Anyone can read this code, including you, a journalist, or an independent security researcher.
This is different from closed-source software, where the code stays private. With open source, people don't have to just trust the company's claims. They can check the code and see for themselves.
Is open source software actually more secure?
Not automatically. Publishing code doesn't fix bugs by itself. A company still needs to write good code and fix problems when they're found.
What open source does is make security checkable. Independent researchers can look for weaknesses, and often do. Closed-source software depends entirely on the company's own internal testing, which outsiders can't verify.
Why does open source matter for privacy specifically?
Privacy claims are easy to make and hard to check. A company can say "we don't track you" or "we don't read your messages." Without open source code, you have no way to confirm this.
With open source, someone can actually read the code and see what the software does. If the company's claims don't match the code, researchers usually find out. This turns a privacy promise into something that can be checked.
Is open source software always free to use?
No. Open source refers to the code being visible, not the price. Many open source products are free, but plenty are also paid.
A company can publish its code openly and still charge for hosting, support, or extra features. Open source and free pricing are two separate things that often get mixed up.