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Security Onion vs Splunk Enterprise Security comparison

 

Comparison Buyer's Guide

Executive SummaryUpdated on Apr 6, 2025

Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:
 

Categories and Ranking

Security Onion
Ranking in Log Management
20th
Average Rating
7.6
Reviews Sentiment
5.5
Number of Reviews
3
Ranking in other categories
AWS Marketplace (11th)
Splunk Enterprise Security
Ranking in Log Management
2nd
Average Rating
8.4
Reviews Sentiment
7.6
Number of Reviews
312
Ranking in other categories
Security Information and Event Management (SIEM) (1st), IT Operations Analytics (1st)
 

Mindshare comparison

As of June 2025, in the Log Management category, the mindshare of Security Onion is 5.3%, up from 4.0% compared to the previous year. The mindshare of Splunk Enterprise Security is 7.3%, down from 10.4% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Log Management
 

Featured Reviews

Jörg Kippe - PeerSpot reviewer
A mature and affordable solution that is easy to install and easy to update
The product takes time to learn, it's not that easy. In the beginning we had a lot of questions. If you want to use such a tool in an real (industrial) environment, you have to ask how to get the network data. Can we do a full packet capture? Can we provide agents to our end systems? There are no simple solutions to these questions. It's a general problem when running such systems in an industrial environment.
ROBERT-CHRISTIAN - PeerSpot reviewer
Has many predefined correlation rules and is brilliant for investigation and log analysis
It is very complicated to write your own correlation rules without the help of Splunk support. What Splunk could do better is to create an API to the standard SIEM tools, such as Microsoft Sentinel. The idea would be to make it less painful. In ELK Stack, Kibana is the query language with which you can search log files. I believe Splunk has also a query language in which they search their log files, but once you have identified the log file that you want to use for further security correlation, you want to very quickly transport that into your SIEM tool, such as Microsoft Sentinel. That is something that Splunk could make a little bit less painful because it is a lot of effort to find that log file and forward it. An API with Microsoft Sentinel or a similar SIEM tool would be a good idea.

Quotes from Members

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:
 

Pros

"Security Onion is the most mature solution in the market."
"We use Security Onion for internal vulnerability assessment."
"The most valuable feature of Security Onion for security monitoring is its ability to find infected ports."
"The stability of Splunk Enterprise Security is very impressive; it is a very stable product."
"The tool helps with advanced reports and keeps the system scalable and flexible. It provides a clear picture of the current status of any incidents. As a CISO, I see a lot of potential for future innovation, which is interesting. I've noticed better performance, especially with the reports."
"Three features stand out for me: the SDK for writing Python, the customizable and adaptable diagnostic dashboard, and the optimizer for collecting data."
"We primarily use it to correlate logs throughout the enterprise for both searching and use in investigations."
"I have not seen any outages in the product in the past two years that it has been running in our company, so I think it is good when it comes to the stability part."
"I like the search feature and the indexing. It's very fast and comprehensive."
"Its usability is the best part. It is easy for our developers to use if they want to search their logs, etc."
"It's very flexible. If you look from the cloud implementation it is there. Reports are made quickly. Unlike other tools, it caters to all kinds of technical information on the front very easily. There's no need to put in any technical information. You can pull on the reports very easily, take action, and notify stakeholders."
 

Cons

"The initial setup of the solution is a little bit difficult."
"The product is not easy to learn."
"Security Onion's user interface could be improved."
"Features related to content management must be improved."
"In the next releases, I would like to see more pricing flexibility."
"Licensing costs can be a barrier for those with limited budgets."
"Splunk can be an expensive solution. Technical support could be improved as well."
"It will be helpful for customers if they can create some real-world cases, and we can find a case study to align with. I know that Splunk has tremendous potential. We only include a tiny piece of it. There is a lot of stuff that we need to learn. If Splunk can provide more real-time examples, that will be helpful for customers."
"It is a hugely complicated product."
"Integrating tools and creating use cases could be easier. It's hard for a junior security engineer with only a couple of years of experience to write use cases. They can do it, but it's much easier in a solution like IBM QRadar. Setting conditions is like a multiple-choice type of thing. It's a more user-friendly process."
"It works as intended for us, and we are getting everything that we need out of it. If anything, its initial setup can be improved a bit."
 

Pricing and Cost Advice

"It is an open-source solution."
"Security Onion is a free solution."
"Security Onion is an open-source solution."
"Our customers often complain that the price of Splunk is too high."
"Splunk is really expensive compared to all the other tools on the market, including Microsoft Sentinel."
"While licensing can be a concern, there are ways to reduce the licensing costs including filtering some events."
"The cost is on the high end, which makes it difficult for some organizations to use."
"Splunk's costing is a little more difficult. The pricing method is complicated, and the way that costing is calculated in Splunk is a little more difficult."
"The pricing of Splunk Enterprise Security is somewhat high, but comparing it with its benefits, it's acceptable. It depends on the type of business."
"Splunk is really expensive."
"Splunk is definitely not a cheap solution. It is an expensive product."
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Comparison Review

VS
Feb 26, 2015
HP ArcSight vs. IBM QRadar vs. ​McAfee Nitro vs. Splunk vs. RSA Security vs. LogRhythm
We at Infosecnirvana.com have done several posts on SIEM. After the Dummies Guide on SIEM, we are following it up with a SIEM Product Comparison – 101 deck. So, here it is for your viewing pleasure. Let me know what you think by posting your comments below. The key products compared here are…
 

Top Industries

By visitors reading reviews
Computer Software Company
11%
University
11%
Government
11%
Comms Service Provider
11%
Financial Services Firm
15%
Computer Software Company
15%
Manufacturing Company
8%
Government
7%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
No data available
 

Questions from the Community

What do you like most about Security Onion?
The most valuable feature of Security Onion for security monitoring is its ability to find infected ports.
What is your experience regarding pricing and costs for Security Onion?
Security Onion is an open-source solution. On a scale from one to ten, where ten is expensive and one is cheap, I rate the solution's pricing a six out of ten.
What needs improvement with Security Onion?
The initial setup of the solution is a little bit difficult.
What SOC product do you recommend?
For tools I’d recommend: -SIEM- LogRhythm -SOAR- Palo Alto XSOAR Doing commercial w/o both (or at least an XDR) is asking to miss details that are critical, and ending up a statistic. Also, rememb...
What is a better choice, Splunk or Azure Sentinel?
It would really depend on (1) which logs you need to ingest and (2) what are your use cases Splunk is easy for ingestion of anything, but the charge per GB/Day Indexed and it gets expensive as log ...
How does Splunk compare with Azure Monitor?
Splunk handles a high amount of data very well. We use Splunk to capture information and as an aggregator for monitoring information from different sources. Splunk is very good at alerting us if we...
 

Overview

 

Sample Customers

Information Not Available
Splunk has more than 7,000 customers spread across over 90 countries. These customers include Telenor, UniCredit, ideeli, McKenney's, Tesco, and SurveyMonkey.
Find out what your peers are saying about Security Onion vs. Splunk Enterprise Security and other solutions. Updated: June 2025.
856,873 professionals have used our research since 2012.