Course
Introduction to OSINT
Centri, formerly Security Blue Team
A free five-hour beginner course from a blue-team training house, with a capstone. Useful as a structured first pass; stop there and move to practice.
Centri's Introduction to OSINT is the OSINT module of a widely used junior analyst pathway, offered on its own for free. It covers the intelligence lifecycle, securing yourself online, a tour of tools and services, and a capstone exercise. It is the most cited free certificate-bearing beginner course in third-party roundups.
Worth it if
- You want a tidy, finishable overview before anything longer
- You are on a security team and need the vocabulary quickly
- You want a completion certificate for a training record at work
Skip it if
- You have already done OSINT Dojo's Student rank or a few TryHackMe rooms; this will repeat them
- You need investigation methodology rather than a tool tour
What is inside
- 01
Intelligence
The intelligence lifecycle and where OSINT sits in it.
- 02
Securing yourself online
Why your own footprint matters before you research anyone else's.
- 03
Tools and services
Search operators, social media search, reverse image search, the OSINT Framework directory, and harvesting tools such as theHarvester.
- 04
Course capstone
A guided exercise that uses the tools from the previous section together.
What you will be able to do
- Describe the intelligence lifecycle and apply it to a small research task
- Use search operators and reverse image search on purpose
- Explain the basic OpSec you need before you start investigating
How current it is
The provider rebranded from Security Blue Team to Centri in 2026 and says earlier certificates remain valid. The course is current on the new platform. Tool-specific lessons will age faster than the lifecycle material.
- Updated
- Provider rebranded to Centri in 2026; course current
- Maintained
- Actively maintained
How to get the most from it
- 01
Finish it in one week
Five hours is short enough to do in a few sittings. Do not let it linger.
- 02
Do the capstone twice
Once as guided, once from memory a week later.
- 03
Move to practice immediately
This course gives vocabulary. The free rooms and exercises listed alongside it give skill.
Strengths
- Free, short, and structured
- Comes from an established training provider
- Capstone ties the pieces together
Limitations
- Tool tour rather than methodology
- Beginner only
- Certificate status after the rebrand is not stated on the page
Pair it with
- ReadCourseFreeBeginner
OSINT Dojo
The structure to continue with after the overview.
- ReadCourseFree + paidBeginner
TryHackMe OSINT rooms
Hands-on rooms for the tools this course introduces.
- ReadBookPaidIntermediate
Intelligence-Driven Incident Response
If you are on a security team and want the lifecycle material taken much further.
FAQ
Questions, answered
Is this the same course as the Security Blue Team one?
Yes. Security Blue Team became Centri in 2026 with the same ownership. The old course URL redirects to the new one, and prior certificates stay valid.
Does it still issue a certificate?
The older page said an e-certificate follows the final exam. The current page does not mention it. Check inside the course before you count on it.
Learned the method? Practise it on real data
The resources above teach the craft. When you want to run real lookups across breach, people, domain, and crypto sources without opening a dozen vendor accounts, that is what SearchIn is for.
- Free account, no card
- Credits never expire
- Refund unused balance in 7 days