The verdict in three sentences
A serious web application security audit costs between 4,500 and 15,000 EUR (excl. VAT) in 2026, depending on the surface to cover and the depth of the pentest. The range hinges on three variables: scope (front-end, API, mobile), person-days (5 to 12) and access level (black-box vs white-box). Budget an additional 20-40% of the audit cost for remediating critical findings plus a validation retest.
What an audit covers and what it costs
An application audit typically combines an automated scan, an OWASP Top 10 review and a manual penetration test. The report must be actionable for your developers: each vulnerability rated (CVSS), with proof of exploitation and a fix recommendation.
| Service | Person-days | 2026 price (EUR excl. VAT) | Retest included |
|---|---|---|---|
| Scan + light OWASP review | 2-3 | 2,500 - 4,000 | No |
| Standard web app audit | 5-7 | 4,500 - 8,000 | Yes (1 round) |
| Audit + API/mobile pentest | 8-10 | 8,000 - 12,000 | Yes (1 round) |
| Full enterprise audit | 10-12 | 12,000 - 15,000 | Yes (2 rounds) |
| Guided remediation | 3-6 | 20-40% of audit cost | - |
Black-box or white-box: the real price driver
Access level radically changes the report's value. In black-box, the auditor simulates an external attacker with no information. In white-box, they receive source code and accounts: more expensive, but far more exhaustive.
| Criterion | Black-box | Grey-box | White-box |
|---|---|---|---|
| Access provided | None | User accounts | Code + admin accounts |
| Surcharge vs base | Reference | +15% | +30 to 40% |
| Detection rate | ~55% | ~75% | ~90% |
| Recommended cadence | Annual | Annual | Every major rebuild |
| Typical duration | 5-7 d | 7-9 d | 9-12 d |
To frame the stakes: the average cost of a data breach for a European SME runs into the tens of thousands of euros (notification, lost contracts, restoration) - a 2026 order of magnitude far beyond an 8,000 EUR preventive audit.
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Mini case study
Marc, IT director of a SaaS vendor in Berlin, must deliver an audit to an industrial client before signing a 180,000 EUR/year contract. He picks a grey-box audit at 9,500 EUR (excl. VAT) (9 person-days, API + front). The audit surfaces 3 critical and 7 medium flaws. Guided remediation costs 3,200 EUR (34% of the audit cost), retest included. Total: 12,700 EUR to secure a 180,000 EUR/year contract, i.e. 7% of first-year revenue. The enterprise client approves and signs.
FAQ
How often should an application be audited? At least once a year, and always after a major rebuild or the addition of a sensitive feature (payment, authentication). An annual cadence covers most 2026 contractual requirements.
Is the retest always included? Not automatically. Standard audits include 1 retest round; check the quote, as a separately billed retest often costs 1,000 to 1,500 EUR.
What is the difference between an audit and a pentest? The audit is holistic (config, code, OWASP); the pentest is a targeted intrusion test. A good quote combines both, with 5 to 12 person-days depending on scope.
Does an audit guarantee zero flaws? No. It sharply reduces risk and proves due diligence, but security is continuous: hence the value of an annual cadence and fast remediation.
How much should I budget for remediation? Expect 20-40% of the audit cost depending on the number of critical flaws. It is the line item companies most often underestimate.
Let's scope your project. Describe your scope (front, API, mobile), tech stack and client deadline, and we will frame the audit and an indicative budget. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
