The core difference: what question are you asking?
Security teams often compare these tools as if they compete. They don't. Each answers a fundamentally different question about a different part of your attack surface.
Is my web application exploitable from the outside?
Can an attacker move through my infrastructure undetected?
What can a skilled attacker do to my specific application?
If you're a dev team shipping a web application, the question you need to answer is the first one. DAST is your tool. BAS is built for enterprise SOC teams validating whether their detection infrastructure works — it doesn't test web app vulnerabilities at all.
Each tool in detail
The question it answers
Is my web application exploitable from the outside?
How it works
Sends real HTTP requests to a running application, observes responses, and confirms vulnerabilities with proof. Works exactly the way an attacker does — from outside the codebase, against the live app.
Finds
- ✓SQL injection, XSS, command injection
- ✓Authentication bypass and session flaws
- ✓CORS misconfigurations and API authorization gaps
- ✓SSRF, IDOR, JWT weaknesses
- ✓OWASP Top 10 across any tech stack
Doesn't find
- ✗Business logic flaws requiring human understanding
- ✗Infrastructure or network-level vulnerabilities
- ✗Static code issues that don't manifest at runtime
Typical cost
Free to €500/month (accessible tier) · €10,000–€60,000/year (enterprise tier)
Who it's for
Dev teams, engineering leads, startups, any team shipping web applications
Examples
Nautillo Pro, Detectify, Probely (accessible) · Veracode, Acunetix, Checkmarx (enterprise)
The question it answers
Can an attacker move through my infrastructure undetected?
How it works
Simulates adversary behaviour across an entire infrastructure — network lateral movement, Active Directory attacks, endpoint compromise, firewall rule validation, email phishing paths. Tests whether your security controls actually stop the attack, not just whether vulnerabilities exist.
Finds
- ✓Gaps in network segmentation and firewall rules
- ✓Active Directory misconfigurations and privilege escalation paths
- ✓Endpoint detection and response (EDR) blind spots
- ✓Email gateway bypass and phishing exposure
- ✓SOC detection coverage gaps
Doesn't find
- ✗Web application vulnerabilities (SQL injection, XSS, IDOR)
- ✗API security issues
- ✗Application-layer authentication flaws
Typical cost
€30,000–€150,000/year · enterprise contracts only
Who it's for
Enterprise security teams with dedicated SOC, SIEM infrastructure, and security operations budget
Examples
Cymulate, AttackIQ, SafeBreach, Picus Security
The question it answers
What can a skilled attacker do to my specific application or system?
How it works
A qualified consultant spends a fixed number of days probing your application using a combination of automated tools and human judgment. Finds vulnerabilities that require understanding business logic, chaining multiple low-severity issues, and reasoning about what the application is supposed to do.
Finds
- ✓Business logic flaws and multi-step attack chains
- ✓Authentication abuse requiring contextual understanding
- ✓Complex privilege escalation paths
- ✓Findings that satisfy compliance certification requirements
- ✓Novel attack paths specific to your application
Doesn't find
- ✗Everything — scope and time are fixed, coverage is point-in-time
- ✗Regressions introduced after the engagement ends
- ✗New vulnerabilities in features shipped post-engagement
Typical cost
€4,000–€25,000 per engagement · retesting typically separate
Who it's for
Any team with compliance requirements (SOC 2, PCI DSS, ISO 27001) or needing depth coverage of complex business logic
Examples
Any accredited penetration testing firm
Why most dev teams don't need BAS
BAS tools are designed for enterprise security operations centres with dedicated analysts, SIEM infrastructure, and security budgets measured in six figures. They answer the question "does our detection stack catch an attacker who has already broken in?"
If you don't have a SOC, an EDR platform, Active Directory, and a security team running it — BAS adds no value. You need to secure the application first before you can validate whether your detection infrastructure is catching attackers who've breached it.
For a dev team or engineering-led security programme, the right sequence is: fix the exploitable vulnerabilities in your web application first (DAST), then run a manual pentest for depth and compliance (when you need it), then think about infrastructure-level detection and BAS if your organisation grows to that scale.
The case for combining DAST and manual pentests
DAST and manual pentests are genuinely complementary. They cover different parts of the same surface.
Run DAST before the pentest
Clear OWASP Top 10 findings your developers can fix in an afternoon. Give the pentest team the surface area that actually requires human judgment — business logic, complex authentication flows, multi-step attack chains.
Run DAST after the pentest
Verify remediation immediately after each fix. Know whether the remediation held without waiting for the next scheduled engagement or paying for a separate retest window.
Run DAST between engagements
Catch regressions as they ship. A quarterly pentest is a point-in-time snapshot. Your application changes daily. DAST coverage between engagements means you're not discovering issues from three months ago at the next engagement.
How to choose
You ship a web application and want to know if it's exploitable
DASTYou need a report to satisfy a compliance audit (SOC 2, PCI DSS)
Manual PentestYou want to verify fixes after remediation without a new invoice
DASTYou have complex business logic that needs a human to assess
Manual PentestYou have a SOC and want to validate your detection coverage
BASYou're a startup prepping for enterprise security questionnaires
DAST + Manual PentestYou deploy continuously and need coverage on every release
DASTDAST for dev teams — free to start
Nautillo Pro runs automated vulnerability scans against your web application with HTTP proof for every confirmed finding. Run before your pentest, run on every deployment, verify every fix. No agents, no code access, no credit card.