SAST vs. DAST: Differences, Use Cases, and When to Use Each

Finding a vulnerability before an application goes live is very different from finding one that only appears when the application is running. That distinction is at the heart of static application security testing (SAST) vs. dynamic application security testing (DAST).

Treating this as an either/or choice can leave gaps. Without SAST, code-level weaknesses that could have been surfaced earlier may travel further down the development pipeline. Without DAST, runtime issues such as authentication weaknesses or deployment misconfigurations may remain invisible to static analysis alone.

This guide breaks down how SAST and DAST differ, where each fits in the software development lifecycle (SDLC), how IAST complements these approaches, and which tools G2 reviewers rate highest for each.

Comparison between SAST and DAST

SAST and DAST approach the same goal of finding application security weaknesses from different points in the development process. The differences become clearer when you compare what each method can see, when it can run, and the types of information it provides to security and development teams.

What is SAST?

Static application security testing (SAST) inspects an application's source code, bytecode, or binaries for security flaws without running the application. It's a white-box method in which the tool has full visibility into the code itself, just as a developer would when reading a file.

How does SAST work?

SAST tools scan code against predefined rules and security patterns to identify potentially unsafe functions, data flows, coding practices, and paths through which untrusted input could reach sensitive operations.

Because the analysis occurs before the application is deployed, SAST can be integrated into developer workflows, including IDEs, repositories, pull requests, and CI pipelines. This allows developers to investigate findings while the relevant code is still being written or reviewed.

Depending on the tool, a SAST finding may include the affected file, the line of code, the vulnerability category, the severity, and remediation guidance. That code-level context is one of the main reasons SAST is useful for shifting security checks earlier in the SDLC.

What vulnerabilities can SAST detect?

SAST is best suited to weaknesses that can be identified from the application’s code or data flow. Depending on the scanner and programming language, these can include:

• Injection-prone code paths
• Path traversal weaknesses
• Unsafe input handling
• Hardcoded credentials or secrets
• Insecure use of cryptographic functions
• Improper error handling
• Potential cross-site scripting flaws
• Security issues caused by unsafe APIs or functions

Coverage varies by tool, language, framework, and rule set, so SAST should not be treated as a guarantee that every code-level vulnerability will be detected.

Advantages of SAST

One of SAST’s biggest advantages is timing. Because it does not require a running application, teams can identify security weaknesses earlier, when developers still have direct context around the code being changed.

SAST can also provide detailed remediation context. When a scanner traces a finding back to a specific file, function, or line, developers have a clearer starting point for investigation than they might get from an externally observed vulnerability alone.

Another advantage is repeatability. Once integrated into the development workflow, SAST can automatically scan new code as it moves through pull requests and builds, helping teams apply security checks consistently.

Limitations of SAST

SAST cannot observe how the application behaves once it is running. That means it may miss vulnerabilities arising from deployment configurations, authentication flows, infrastructure settings, or interactions between components at runtime.

It can also generate findings that require developer review before they are confirmed as exploitable. The volume and accuracy of those findings depend heavily on the scanner, application architecture, rule configuration, and supported programming languages.

For that reason, SAST provides strong visibility into code-level risk, but it does not replace testing that evaluates the application in its running environment.

10 best SAST tools on G2

The examples below are selected based on the highest G2 Scores in the Fall 2026 Grid® Report for SAST software. G2 Scores reflect a combination of customer satisfaction and market presence, rather than star ratings alone. Ratings can change as new reviews are added, and inclusion here should not be interpreted as a ranked recommendation.

When comparing SAST tools, teams should also consider factors such as language coverage, scanning accuracy, development-workflow integrations, remediation guidance, and test automation.

What is DAST?

Dynamic application security testing (DAST) tests a running application from the outside, without any access to its source code. It's a black-box method in which the tool interacts with the application the same way a real user (or attacker) would: sending requests, observing responses, and probing for weaknesses in whatever comes back.

How does DAST work?

DAST tools crawl or discover an application's accessible pages, endpoints, and inputs, then send test requests designed to expose vulnerabilities. The scanner observes how the application responds to these requests and flags behavior that may indicate a security issue.

This allows DAST to evaluate the application in a functioning environment, where factors such as authentication, server configuration, APIs, and interactions between application components can affect security.

DAST can also be incorporated into CI/CD workflows once a testable application is available. Teams may run scans against test or staging environments as part of release validation, with the timing and depth of scanning depending on the application and testing strategy.

What vulnerabilities can DAST detect?

DAST is particularly useful for vulnerabilities that become observable through an application's runtime behavior. Depending on the tool and application, it can identify issues such as:

• SQL injection
• Cross-site scripting (XSS)
• Authentication and session-management weaknesses
• Security misconfigurations
• Exposed or vulnerable application endpoints
• Improper input validation
• Insecure HTTP headers
• Server and application configuration issues

Because DAST interacts with the application externally, its coverage depends on what the scanner can discover and reach. Vulnerabilities hidden behind untested workflows, inaccessible endpoints, or complex authentication flows may require additional configuration or other testing methods to uncover.

Advantages of DAST

A key advantage of DAST is its ability to evaluate security in the context of a functioning application. It can expose weaknesses caused not only by application logic but also by configuration and runtime behavior that aren't visible through code analysis alone.

DAST is also largely independent of the programming language used to build the application. Because testing happens through exposed interfaces, teams can assess applications built with different languages and frameworks without requiring the scanner to analyze each underlying codebase.

Its findings can also provide evidence of how a vulnerability manifests through a request, response, endpoint, or user-facing behavior. This can help security teams understand the externally observable risk.

Limitations of DAST

DAST can only test functionality it can reach. If the scanner cannot discover an endpoint, navigate a workflow, or authenticate into a protected area, vulnerabilities in those paths may remain untested.

Findings also don't always reveal the exact line of code responsible for a vulnerability. Developers may need to trace an externally observed issue back through the application's logic to identify its root cause.

And because DAST requires a functioning application, it cannot provide the same early code-level feedback that developers receive when writing or reviewing code. This makes it most useful as another layer of application security testing rather than a substitute for earlier security checks.

10 best DAST tools on G2

The examples below are selected based on their G2 Scores in the Fall 2026 Grid® Report for DAST software. The G2 Score combines customer satisfaction and market presence to reflect a product's position in the category. Ratings can change as new reviews are added, and inclusion here is not a ranked recommendation.

Teams evaluating DAST tools should also consider scan coverage, authenticated testing, API support, CI/CD integrations, remediation workflows, and how easily the scanner can reach the application's relevant attack surface.

When should you use SAST vs. DAST?

The choice depends on the stage of development and the type of risk you need to investigate. SAST is most useful when teams still have direct access to the code being changed, while DAST becomes valuable once there is a functioning application whose runtime behavior can be tested.

When should you use SAST?

Use SAST when you want security checks embedded into the development process. SAST is particularly useful when:

• Developers need feedback while coding. IDE and repository integrations can surface potential weaknesses close to where they're introduced.
• You want checks before code is merged. SAST can scan pull requests and builds before changes progress further through the pipeline.
• Developers need remediation context. Findings can often point to the affected file, function, or line of code.

When should you use DAST?

Use DAST when you have a functioning application and need to evaluate security weaknesses exposed through its actual behavior. DAST is particularly useful when:

• Your application depends on services or components you don't control. DAST tests the assembled system the way an outside user would encounter it, catching issues that only emerge once all the pieces are interacting — not just the code you wrote yourself.
• You want to assess exposed attack surfaces. DAST can probe reachable pages, inputs, APIs, and endpoints.
• You're validating a testable release. Teams can scan applications in testing or staging environments before deployment.

Do you need both SAST and DAST?

SAST and DAST provide complementary visibility for applications that require both code-level and runtime security testing.

A team might run SAST as developers commit and review code, then use DAST against a functioning build later in the delivery pipeline. Neither method guarantees that every vulnerability will be discovered, so manual testing and other security techniques may still be necessary for risks such as complex business-logic flaws.

How does IAST differ from SAST and DAST?

Interactive application security testing (IAST) analyzes an application from within while it is running. It typically instruments the application during functional or security testing and observes code execution, data flow, requests, and runtime behavior.

This gives IAST some of the runtime context associated with DAST while also providing internal application context that can help connect a finding to the relevant code path, method, or line.

IAST isn't simply SAST and DAST running together. It uses its own runtime analysis approach and depends on application functionality being exercised during testing. If a workflow isn't executed, vulnerabilities within that path may not be observed.

IAST can also reduce some of the noise associated with purely static analysis because findings are informed by code that actually executes during testing. However, accuracy and coverage still depend on the tool, application, instrumentation, and test coverage.

Because IAST requires a running application, it doesn't replace security checks that happen earlier in development. It is often used alongside SAST rather than as a direct substitute.

How do SAST and DAST fit into the SDLC?

SAST and DAST create security checkpoints at different stages as an application moves from code to a running environment.

A simplified workflow looks like this:

Code → Commit and pull request → Build → Test/staging → Deploy → Monitor

• SAST: Code → Commit/pull request → Build
• SCA: Code/build → Dependency analysis
• DAST: Test/staging → Deployment validation
• IAST: Functional and security testing of a running application

SAST can begin while code is being written and continue through pull requests and builds. DAST enters the workflow once there is a functioning application to test and can be rerun as new builds become available.

This layered approach is part of DevSecOps, where security checks are integrated throughout the software delivery process rather than reserved for a final pre-release gate.

SAST vs. DAST vs. IAST vs. SCA

SAST and DAST aren't the only approaches used in application security testing. Interactive application security testing (IAST) and software composition analysis (SCA) address different aspects of application risk, so they complement rather than replace SAST and DAST.

Where does SCA fit?

Software composition analysis (SCA) focuses on third-party and open-source components used to build an application.

SCA tools identify dependencies and compare them with vulnerability and component data to help teams find known risks in external packages. Depending on the product, they may also provide information about licenses, dependency relationships, and remediation options.

SAST, DAST, IAST, and SCA therefore address different parts of application risk. They are better understood as complementary layers of application security testing than interchangeable alternatives.

Frequently asked questions about SAST vs. DAST

Got more questions? Here are the answers. 

Q. Is SAST better than DAST?

Neither SAST nor DAST is inherently better because they test applications from different perspectives. SAST is better suited to identifying code-level weaknesses during development, while DAST evaluates vulnerabilities that become observable in a running application. The appropriate approach depends on the risk being tested and the SDLC stage.

Q. Can DAST replace SAST?

No. DAST cannot provide the same visibility into an application's underlying code as SAST. Because DAST interacts with a running application externally, it may not encounter vulnerable code paths during testing. SAST can examine those paths directly, even if they aren't exercised at runtime.

Q. Does DAST require access to source code?

No. DAST performs black-box testing against a functioning application and doesn't require access to its source code. This makes it useful for testing the behavior of externally accessible applications, even when the underlying codebase isn't available to the tester.

Q. Can SAST and DAST replace penetration testing?

SAST and DAST automate the discovery of many application security weaknesses, but they don't eliminate the need for manual penetration testing. A skilled penetration tester can investigate attack paths, chained vulnerabilities, authorization problems, and business-logic flaws that automated scanners may not reliably identify.

Q. Is SonarQube a SAST or DAST tool?

SAST. SonarQube analyzes source code for security issues and code-quality problems together, without executing the application, which places it squarely in the static testing category.

Q. What are the most trusted SAST platforms among security engineers and developers based on user reviews?

Aikido Security, GitHub, GitGuardian, GitLab, and SonarQube lead the Fall 2026 G2 Grid Scores for SAST software, with scores ranging from 71 to 89. Aikido Security ranks highest at 89, followed by GitHub at 82 and GitGuardian at 80. These scores combine satisfaction and market presence, making them useful for shortlisting established options, although they don't represent developer-specific ratings.

Q. Which SAST tools are best for teams of 100–500 employees managing code vulnerabilities?

GitHub, GitLab, Semgrep, and Snyk are worth evaluating for mid-sized development teams. GitHub and GitLab integrate security scanning into existing development workflows, while Semgrep supports customizable scanning rules and Snyk emphasizes developer-focused security testing. The right choice depends on language coverage, repository integrations, security expertise, and remediation requirements rather than company size alone.

Q. Which SAST platforms integrate with existing remediation and issue-tracking workflows?

GitHub, GitLab, Snyk, and Semgrep offer ways to incorporate security findings into development workflows. GitHub and GitLab are particularly relevant for teams already managing code and issues within their ecosystems, while Snyk and Semgrep provide integrations with supported development tools. Teams should verify compatibility with their existing issue trackers, CI/CD pipelines, and remediation processes before choosing a platform.

Q. Which DAST platforms are most trusted by penetration testers and engineering teams?

Aikido Security, Astra Pentest, Burp Suite, GitLab, and Invicti are among the highest-scoring DAST platforms in G2's Fall 2026 Grid Report. Aikido Security leads with a G2 Score of 80, followed by Astra Pentest at 74 and Burp Suite at 70. Burp Suite is particularly relevant to penetration testers who need hands-on testing capabilities, while GitLab appeals to teams incorporating DAST into development pipelines. The Grid Scores reflect overall category performance, not ratings isolated to penetration testers or engineering leaders.

Q. Which DAST tools are best for manual penetration testing and reducing testing effort?

Burp Suite and Cobalt are useful options for teams combining manual penetration testing with structured security assessments. Burp Suite provides tools for investigating vulnerabilities and automating portions of testing, while Cobalt connects organizations with penetration testing services. Automated DAST tools such as Invicti and Astra Pentest can also help identify vulnerabilities before manual assessments. However, lower testing costs or reduced audit preparation time depend on the organization's application complexity, testing scope, and existing security processes.

Q. Which DAST platforms also provide SAST and SCA capabilities?

Aikido Security and GitLab are worth considering when teams want multiple application security testing capabilities within a broader platform. Aikido Security integrates application security scanning with other security capabilities, while GitLab incorporates security testing into its DevSecOps workflows. Other DAST products may focus more narrowly on runtime testing, requiring separate tools for static code analysis or dependency scanning. Teams should confirm which SAST, DAST, and SCA capabilities are included in their chosen plan.

Q. Can DAST tools automatically detect business-logic flaws and complex vulnerabilities?

DAST tools can identify many vulnerabilities exposed through application behavior, but they cannot reliably detect every business-logic flaw. Complex authorization problems, multi-step workflow abuse, and vulnerabilities requiring application-specific context may escape automated scans. Tools such as Burp Suite support deeper manual investigation, making automated DAST and human-led penetration testing complementary rather than interchangeable.

Q. Which DAST tools support API testing and automatic endpoint discovery?

Qodex.ai is built specifically for AI-automated API security testing, including GraphQL and REST APIs, without requiring manual test configuration. Intruder is the stronger fit for automatically discovering an application’s broader external attack surface, continuously scanning for new or forgotten endpoints rather than testing a known API spec.

Q. Which SAST tools are easiest to adopt without deep security expertise?

Aikido Security and GitHub (via GitHub Advanced Security/CodeQL) are built to run inside workflows developers already use, surfacing findings directly in pull requests rather than requiring a separate security console or dedicated analyst to interpret results. Checkmarx, by contrast, offers deeper configurability that typically benefits from a security engineer tuning rules and triaging findings.

Q. Which SAST tools integrate most reliably into CI/CD pipelines?

GitLab and GitHub are the strongest fits here since SAST is native to the platform teams are already using for version control and builds, removing a separate integration step entirely. Semgrep and Snyk are also built around CI/CD-first workflows, with rule-writing and pull-request feedback designed to slot into an existing pipeline rather than bolt onto it.

Test the code and the application

SAST vs. DAST isn't really a matter of choosing one security testing method and ignoring the other. The more useful question is where a vulnerability can appear and when your team has the best chance of finding it.

If the risk is visible in the code, SAST gives developers a chance to investigate it while they're still writing, reviewing, or building the application. Once that application is running, DAST adds another perspective by testing what is actually exposed through its interfaces, configuration, authentication flows, and runtime behavior.

From there, teams can add other layers such as SCA for third-party dependencies, IAST for runtime analysis with internal context, and manual penetration testing for vulnerabilities that automated scanners may miss.

The goal isn't to run every available security tool. It's to build enough coverage across the SDLC that code-level, dependency, runtime, and application-specific risks aren't all being left to the same testing method.

Automated testing still leaves some attack paths and business-logic risks for human-led validation. If that is the next gap in your security stack, compare the penetration testing tools G2 evaluated for 2026.

This article was originally published in 2019 and has been updated with the latest information and G2 Data.