Live Chat
Same Certs
Cheapest Price Seal
Less Price

What is the Difference Between SAST, DAST, and IAST?

What is the Difference Between SAST, DAST, and IAST

The essence of mobile & web application testing is to eliminate the possibility of code flaws and ensure that the application functions optimally. Developers should squash out bugs before they are included in the final software release. Doing so will help to keep the application safe from security threats. As a result, your organization is safe from the high costs of security breaches such as reputational and financial damages.

But testing applications and eliminating bugs is no child’s play. Many developers I have interacted with point out several challenges during the application testing process. Some of the challenges include different browsers, cybersecurity risks, and the overall web application integration.

Technologies to Catch Security Flaws Before they are Baked

Thanks to technology, developers and testers can use several tools to spot code flaws and vulnerabilities during different application/software development stages. It is to note that for a developer, application software should be secured with Code Signing Certificate that assures users that the code is not modified since it is signed. There are four types of application security testing technologies. They are;

  • Static Application Security Testing (SAST)
  • Dynamic Application Security Testing (DAST)
  • Interactive Application Security Testing (IAST)
  • Runtime Application Self-Protection

This article explains three application security testing technologies. It explores the difference between SAST, DAST, and IAST. It points out the advantages and disadvantages, among other aspects you should look for when selecting them.

Static Application Security Testing (SAST)

The best way to understand this technology is to ask yourself the question- “Why Static?” Static application security testing is called so because the test is done before the application is launched (goes live). In short, SAST helps developers detect application vulnerabilities and flaws before the world can find them.

How does SAST Work?

Static application security testing carries technologies and tools that check code flaws and vulnerabilities. The tools are essentially vulnerability checkers that crawls through the application to look for flaws and defects. Upon discovering code vulnerabilities, the next course of action will involve patching the code before deploying it live.

The process of using SAST to check, discover and patch code vulnerabilities is sometimes referred to as White Box Testing.

Advantages of SAST

  • Using SAST to fix code vulnerabilities is comparatively cheaper since it comes during the initial stages of the SDLC
  • SAST is 100% automated, meaning it analyzes applications and codes faster than humans
  • SAST offers real-time and fast feedback, alongside graphical representations of issues found
  • This tool points out the exact location of the vulnerability
  • Developers can use the customized reports feature, which can be exported and tracked with dashboards

Disadvantages of SAST

  • SAST will first have to synthesize data to test the code. This might sometimes lead to false positives
  • It is an unsuitable application security testing tool for understanding wireframes or libraries.
  • It is impossible to use SAST to check calls and other argument values.

Dynamic Application Security Testing (DAST)

Dynamic application security testing is a black boxing testing technique. In short, DAST is performed from the inside in. This process includes tools and techniques to scan through running applications to check and unearth security vulnerabilities. The major difference between DAST and SAST is that whereas SAST has a clear view of the code base, DAST cannot see the code base and therefore lacks knowledge of the underlying code.

Dynamic application security testing is designed to find server authentication and configuration hitches, plus all other vulnerabilities visible only after a user logs into the application.

How Does DAST Work?

Please note that DAST carries out its security testing from the outside. The reason is that it does not have access to the source code. For instance, DAST might try out cross-site scripting to feed alphanumeric data to dialogues expecting numerical inputs. The purpose of doing so is to establish how the application deal with the error. In a nutshell, DAST operates as an input simulator that directs predetermined inputs to the application being tested. These are scripted in a manner similar to what a malicious attacker will employ to conduct the attacks. If the application or software responds to an input in a way not expected, then it might be possible that the application might be housing security flaws.

Advantages of DAST

  • Unlike SAST, DAST allows developers to conduct an application security analysis that spots runtime issues. Runtime issues might include things like authentication flaws and network configuration hitches. These flaws usually arise only after a user logs into an account.
  • Although false positives are issues experienced with DAST, they are not as many as those in SAST.
  • DAST is compatible with almost all customized and off-the-shelf frameworks and programming languages.
  • DAST is a pocket-friendly and less complex method of application security testing.

Disadvantages of DAST

  • The dynamic application security tool does not provide insights into the underlying factors that cause application flaws and vulnerabilities. Additionally, the tool is not suitable for maintaining the required coding standards.
  • DAST is not an ideal tool for identifying vulnerabilities in the early stages of the software development life cycle. The reason is that the tool is only used for testing an already operational application.
  • DAST is not well-positioned to simulate potential attacks. Usually, the tool leverages the exploits executed by someone with knowledge of the application.

Interactive Application Security Testing (IAST)

Interactive application testing (IAST) blends the best features of DAST and SAST when carrying out application security testing. IAST is usually employed when the application is in development. When configured perfectly, the interactive application security testing can do the following:

  • Gain access to the code of the software or application
  • Collect data and relevant information relating to the runtime control and data flow
  • Oversee all traffic on the hypertext transfer protocol
  • Gain access to different application components such as libraries, back-end data, and frameworks.

As a result, the IAST tool provides a clear view of the software and application (including the surrounding environment). It is, therefore, a reliable application security testing tool for addressing more code vulnerabilities and detecting security flaws more than its other two counterparts.

How Does IAST Work?

Developers and testers use the interactive application security testing tool to search and detect application flaws and check application performance and many other application issues. Upon completion of all the testing activities, all the problems detected will be directly fed into a tracking tool. One of the most outstanding features of IAST is that it can be applied at any point during the software development life cycle. For instance, application developers can use it during the integrated development environment (IDE) to check the code base. Developers and testers can then follow into application testing and validation and create performance reports over the same issues.

Advantages of IAST

  • One of the best things about IAST is its ability to detect and catch security issues during the early stages of application/software development. And because of its shift-left approach, it remains the most suitable tool for minimizing delays and costs.
  • As is the case with the other two application security testing tools (SAST and DAST), IAST is well-suited to give exhaustive data-containing code lines. With this feature, developers and their security teams can immediately focus on specific security vulnerabilities.
  • Since IAST has access to a wide range of information, it can accurately point out the specific source of code vulnerability.
  • Unlike the other two application security testing approaches, it is possible to integrate IAST into continuous integration and deployment (CI/CD).

Disadvantages of IAST

  • One of the major drawbacks of an integrated application security testing tool is performance. The tool is prone to slowing down the operations of software and applications. The leading cause of slow operations is added instrumentations that come with the tool.
  • IAST is a relatively new technology. As a result, more flaws associated with the tool are yet to be uncovered.

Choosing Between SAST, DAST, and IAST

You now understand what each of the three application security testing technologies means and do. At this point, you are probably wondering what technology to choose. If I were asked to make a choice of the three, I would probably go for all of them. But that does not sound like a pocket-friendly choice.

It is important to note that DAST, SAST, and IAST are excellent technologies that work for the good of your software and application security. If you have the financial muscles to implement them, then be assured of reaping big from the complementary features they will bring forth. Furthermore, implementing all the tools will bring stability to your applications and keep them free from all kinds of security vulnerabilities.


Thanks to the technological revolution and agile environment, it is now possible to automate our security processes. SAST, IAST, and DAST tools are enough proof of the extent of automation. These tools are investments worth dipping your toes into. Cybersecurity, as we know it, is expensive yet necessary. This article has explained what the three tools mean and do, alongside their advantages and disadvantages.

Recommended Reading : 

4.8/5 overall satisfaction rating

Based on 3910 ratings from actual customers

Customer Reviews
"Not a new customer just a new account due to a name change. Love your prices and service. Thanks for everything! Jimmy - Prestacarts Global Commerce"
Jimmy Ray Warren J / TX, United States
"I have to say your tech "Mike" went out of his way to help me setup the CSR for our SSL. I am not a techie, and Mike was extremely helpful and patient with me. You need to hire more support personnel like Mike! Great job Mike!! Thank you for all your help!! Jana"
Jana K
"Been using you guys for several years. Clean built website with a great UI/UX that lets me get to what I need to buy quickly. I couldn't ask for more. Thanks!"
Devin N
5 Star
4 Star
3 Star
2 Star
1 Star