A one-time scan is a single automated check of your website against Web Content Accessibility Guidelines (WCAG) criteria. Monitoring is that same type of scan repeated on a recurring schedule. The cost difference comes down to frequency: one-time scans carry a flat fee, while monitoring involves an ongoing subscription that runs scans daily, weekly, monthly, or on a custom cadence.
| Key Point | What It Means |
|---|---|
| One-Time Scan | A single automated check with a flat fee, typically lower upfront cost |
| Monitoring | Recurring scans on a set schedule, billed as an ongoing subscription |
| Coverage | Both types of scans flag approximately 25% of accessibility issues |
| Value Over Time | Monitoring catches new issues as content changes, reducing the risk of regression |
What Does a One-Time Scan Cover?
A one-time scan loads your web pages and runs automated checks against WCAG success criteria. It evaluates HTML, CSS, and ARIA attributes to flag issues it can detect programmatically. The result is a snapshot of your site at that moment.
This approach works well for a baseline assessment. You get a report showing what the scan identified, and you can use it to prioritize remediation. The limitation is that scans only flag approximately 25% of accessibility issues, so a scan alone does not replace a full audit.
What Does Monitoring Add?
Monitoring runs the same type of automated scan on a recurring schedule. When new pages go live, content gets updated, or code changes, monitoring picks up issues that did not exist during the previous scan.
Websites are not static. A page that passes a scan today may have new issues next week after a content update. Monitoring tracks these changes over time and provides ongoing visibility into your site’s accessibility status.
How Does the Monitoring vs One-Time Scan Cost Break Down?
One-time scans are typically billed as a flat fee based on the number of pages scanned. The cost is predictable and contained to a single payment.
Monitoring is priced as a subscription. Monthly or annual billing is standard. The cost depends on the number of pages covered, the scan frequency, and whether the service includes reporting features or authenticated page scanning. Authenticated scanning, which requires a browser extension running within an active session, covers pages behind logins that a standard scan cannot reach.
Over a 12-month period, monitoring costs more than a single scan. Over that same period, it also produces 12 or more data points instead of one.
Which Makes Sense for Different Situations?
A one-time scan fits when you need a quick baseline or want to evaluate a site before investing in a full audit. It gives you a starting point without a recurring commitment.
Monitoring fits when your site changes frequently, when you have an active remediation program, or when you need to demonstrate ongoing attention to WCAG conformance. Organizations managing multiple sites or large page counts tend to get more value from monitoring because the volume of potential regression is higher.
Neither option replaces a manual audit. Both types of scans flag approximately 25% of issues. The remaining 75% requires human evaluation by an accessibility professional. Monitoring and one-time scans are components of a broader accessibility program, not substitutes for one.