Best Attack Surface Management Tools (2026)
Short answer. If you need to know what your organization exposes to the internet and get evidence you can act on, choose a tool by how it builds its asset list, not by how many checks it advertises. Teams with a dedicated security function and an enterprise budget are well served by the large platforms. Small teams and service providers are usually better off with a focused tool that starts from their own DNS rather than guessing. AYAsec, which we make, is built for the second group - and this page says plainly where it is not the right answer.
How we compared these tools
We make one of these products. AYAsec is ours. We have kept it in the list because leaving it out would be stranger than including it, and we have written the section on where it does not fit as carefully as the rest.
Every criterion is applied to every tool. The same sixteen questions, in the same order, so a difference in the table reflects a difference in the products rather than a difference in what we chose to mention.
Claims are sourced and dated. Where a fact comes from a vendor's own documentation or pricing page, it is dated, because both change. Where we could not confirm something, the table says n/a rather than guessing. An empty cell is more useful than a wrong one.
Quick comparison
| Tool | Best for | Asset discovery model | Provider / zone import | Scan coverage | Free tier | Pricing model | Setup effort |
|---|---|---|---|---|---|---|---|
| AYAsec | Lean teams and MSPs needing inventory plus evidence | Import from your DNS, plus certificate transparency and passive DNS | Yes - 8 providers and zone file upload | 6 types: discovery, TLS, HTTP, ports, DNS, domain credibility | Yes, free forever | Flat per organization | Minutes; domain ownership verification required |
| Attaxion | Broad discovery, comfortable with per-asset pricing | Internet-based discovery | n/a | Broad EASM, same features on every tier | Community Edition after trial: monthly scans, 40 assets, half visible | Per asset: $129 / $349 / $949 for 40 / 120 / 360 | n/a |
| Microsoft Defender EASM | Azure-committed organisations | Internet-based discovery | n/a | Discovery of internet-exposed resources | n/a | On request, via Azure | n/a |
| Censys ASM | Teams wanting internet-scale data | Internet-scale dataset | n/a | n/a | n/a | Credits from $100; plans via contact sales | n/a |
| Detectify | AppSec teams wanting app and API testing too | Surface monitoring; apex discovery from Professional | n/a | Surface monitoring, app and API scanning | Starter at €0 platform fee | Annual platform fee €0 / €2,500 / €5,000 / €15,000 plus per asset | n/a |
| Intruder | Small teams wanting external, internal and cloud in one place | Unknown-asset discovery Enterprise only | n/a | Vulnerability scanning; ports tiered by plan | Yes - 5 targets, weekly, ports 80 and 443 | Base fee plus per target; paid amounts vary by plan | n/a |
| ProjectDiscovery | Engineering-led teams who build | Own open-source tooling | n/a | Pentesting, ASM, red teaming, automation | Community tier | Quote / order form | n/a |
| Cortex Xpanse | Large enterprises | Internet-scale: 500bn ports scanned daily | n/a | Enterprise exposure management | No | On request | n/a |
| Tenable Nessus Expert | Teams already running Nessus | Included external surface scanning | n/a | Vulnerability, web app and external surface | No | US licence: $6,790 / 1yr · $13,208.13 / 2yr · $19,304.19 / 3yr | n/a |
| Invicti Web + API (was Acunetix) | Application security testing | Not its primary job | n/a | Deep authenticated DAST | No | On request | n/a |
| UpGuard | Vendor risk, breach risk and trust exchange | External asset discovery and monitoring | n/a | Vendor risk, breach risk, threat intelligence | Yes | Trust Exchange free; paid $600/month billed annually; Vendor Risk from $1,750/month billed annually; other plans on request | n/a |
| SecurityScorecard | Third-party risk, not your own surface | Not applicable | no | Security ratings, questionnaires, vendor register | Free tier exists | On request | n/a |
The tools in detail
AYAsec
Best for: teams without a dedicated security function, and MSPs or MSSPs managing several clients.
AYAsec starts from the position that an asset list you inferred is worth less than one you were given. You connect a DNS account - Cloudflare, AWS Route 53, Azure DNS, Google Cloud DNS, DigitalOcean, GoDaddy, Hetzner or Contabo - or upload a zone file, and those become monitored assets. Certificate transparency and passive DNS discovery run alongside to find what the zone does not contain.
Before anything is scanned, you prove you control the domain, by DNS record, a file at a known path, or a meta tag. Verifying an apex domain covers its subdomains. Unverified assets are excluded rather than scanned.
Six scan types run against verified assets: discovery, TLS/SSL, HTTP with OWASP ZAP, ports with CVE correlation, DNS including mail authentication records, and domain credibility. Five of them produce a 0-100 score mapped to an A+ to F grade; the composite weights HTTP at 30% and TLS, ports and DNS at 20% each. Reports export as PDF in brief or full form, and can be shared through a public link that needs no account. See how to prove remediation.
Findings come with AYA, an assistant that explains what a finding means and what to do about it, in the report you are looking at.
Pricing is flat per organization, set by scan frequency, team size and workspace count rather than by asset count. Free is free permanently with one member and weekly scans; paid tiers run from €96 to €450 per month, with hourly scanning and SSO at the top. Adding subdomains does not change the price.
The Enterprise tier also includes a Wazuh-backed SIEM solution, delivered as a bespoke project rather than a click-to-enable feature. It can include a per-workspace control panel, alert-rule management, agent provisioning and revocation, and data-retention controls. Additional custom workstation or server configuration and consultation are separately contracted.
Where it is weaker: it is external only, it is not a full web application security scanner, and the ownership verification step slows down a first look compared with tools that scan anything on request.
Attaxion
Best for: teams that want broad external discovery and are comfortable with asset-based pricing.
Attaxion is a broad external attack surface management platform. Every tier includes the same feature set - asset-to-asset mapping, technology discovery, exportable reports, cloud integrations, alerts through email, Slack and Jira, a toggle between passive and active scanning, prioritisation, role-based access and API access.
Pricing is by asset count: $129 per month for up to 40 assets, $349 for up to 120, and $949 for up to 360, with Enterprise on request. Billable assets are domains, subdomains and IP addresses; ports, technologies, certificates and email addresses are counted but not billed. There is a 30-day trial, after which the account drops to a free Community Edition that scans monthly, covers 40 assets and shows you half of them.
Worth knowing before you buy. Attaxion's own pricing FAQ answers the question of what happens when your asset count exceeds your plan: the platform discovers assets you did not know about, "which may result in the actual number of assets exceeding your expectations", followed by an invitation to upgrade. That is an honest description of asset-based pricing, and it is the trade-off to understand going in - the better the discovery works, the more you pay.
Source: Attaxion pricing, checked September, 2026.
Microsoft Defender EASM
Best for: organisations already committed to Azure, where security tooling is expected to live in the same portal and the same bill.
Defender EASM discovers internet-exposed resources and fits into the wider Microsoft security stack. If your identity, cloud and endpoint tooling is already Microsoft, the integration argument is strong and hard to beat on its own terms.
Pricing is not published. The pricing page directs you to the Azure pricing calculator or to sales, and states that the figure depends on region, agreement type and exchange rate.
Where we differ. AYAsec imports assets from eight DNS and hosting providers rather than one cloud. If your estate is genuinely all Azure, that difference matters less; if your DNS sits at Cloudflare and your hosting somewhere else, it matters more.
Source: Microsoft Defender EASM pricing, checked September, 2026.
Censys ASM
Best for: teams that want access to internet-scale data.
Censys built its position on internet-scale data, and that dataset is the reason to choose it. Its current pricing page routes Core, Adversary Investigation and Security Operations plans to contact sales, while credit packages start at $100.
Where we differ. We are not going to claim a better dataset - we do not have the evidence for that and it would be an easy claim to disprove. The difference is in where the asset list starts. Censys works from what it observes on the internet; AYAsec works from what you hand it, through a DNS provider connection or a zone file, with internet-based discovery running alongside rather than instead.
Source: Censys pricing, checked September, 2026.
Detectify
Best for: engineering and AppSec teams that want application and API testing alongside surface monitoring.
Detectify prices as an annual platform fee plus per-asset charges. The platform fee is €0 for Starter, €2,500 for Standard, €5,000 for Professional and €15,000 for Enterprise, and assets - apex domains, subdomains and IP ranges - are charged on top, as are Application Scanning and API Scanning per target, and PCI ASV scanning at €500 per year. Apex discovery, IP range scanning and internal scanning start at Professional.
Detectify also offers domain verification, an MCP server and what it calls agentic tooling.
Where we differ. Two things, and neither is about depth of application testing - theirs is deeper and we are not claiming otherwise. First, the price here is a floor rather than a total: what you pay depends on how many assets you have. Second, apex discovery sits at the €5,000 tier, whereas discovery is the entry point for us rather than an upgrade.
Source: Detectify pricing, checked September, 2026.
Intruder
Best for: small teams that want vulnerability scanning across external, internal and cloud targets from one place.
Intruder has a free tier with five infrastructure targets, weekly external scans and three users. Its current pricing page shows Cloud and Pro tiers but renders their paid amounts through the plan selector; Enterprise is custom. Pricing is a base fee plus a fee per target, which the company states plainly in its own FAQ. Agent-based scanning of internal servers starts at Pro, and there is a separate pentest offering from $3,500 per test.
Two things are tiered in a way worth checking against your needs. Port monitoring runs from ports 80 and 443 on Free, to the top ten on Cloud, the top fifty on Pro, and all ports on Enterprise. And automated discovery of shadow IT and unknown assets is Enterprise-only.
Where we differ. If discovering what you did not know about is the reason you are shopping, note which tier that sits in. All six AYAsec scan types, including discovery, are on every plan including the free one.
Source: Intruder pricing, checked September, 2026.
ProjectDiscovery
Best for: engineering-led security teams who want to build and automate rather than buy a finished workflow.
ProjectDiscovery is the team behind nuclei, subfinder and httpx - tools that a large part of this industry, including us, has used. Its current site routes the commercial platform to a demo, and its terms say fees are set in an order form; I could not confirm public seat pricing. The platform covers application and API pentesting, attack surface management, red teaming and custom automation, with agent run logs exportable to a SIEM, scope guardrails and model selection.
Where we differ. This is the closest thing on this list to a different philosophy rather than a different feature set. They sell capability you assemble; we sell a workflow that runs. If your team enjoys building the pipeline, their tools are excellent and free to start with. If nobody has time to maintain it, that is the case for something finished.
Sources: ProjectDiscovery terms and ProjectDiscovery platform, checked September, 2026.
Cortex Xpanse
Best for: large organisations with an attack surface too big to enumerate by hand, and the budget an enterprise platform implies.
Cortex Xpanse, from Palo Alto Networks, operates at internet scale: the company states it scans 500 billion ports daily and covers 4.3 billion IPv4 addresses multiple times a day. Forrester has named it a leader in attack surface management. Pricing is not published; the route in is a demo.
Where we differ - and this is the clearest contrast on the page. Xpanse scans the entire internet and then works out which of it is yours. AYAsec asks you, through your DNS provider, and scans the internet alongside. Neither approach is wrong. At the scale Xpanse serves, enumerating from the outside is the only option that works. At the scale most teams operate at, being handed the list is both faster and less likely to include somebody else's servers.
Source: Cortex Xpanse, checked September, 2026.
Tenable Nessus Expert
Best for: teams that already run Nessus and want external surface scanning added to a familiar tool.
Nessus Expert covers vulnerability scanning, web application scanning and external attack surface scanning. Tenable's US purchase page lists $6,790 for one year, $13,208.13 for two and $19,304.19 for three; support and training are priced separately. Prices vary by market, so the currency and region matter.
Where we differ. Nessus is a deeper vulnerability scanner than we are and we are not going to pretend otherwise. It is also priced and built for a security function that already exists. If there is no such function, the question is not which scanner goes deeper but which one produces something readable on day one.
Source: Tenable Nessus purchase page, checked September, 2026.
Invicti Web + API (formerly Acunetix)
Best for: teams whose main problem is application security testing rather than asset inventory.
Acunetix is now sold as Invicti Web + API - worth knowing if you are searching under the old name. It is a dynamic application security testing product: deep, authenticated, application-aware scanning. Pricing is by quote.
Where we differ. These solve different problems and are more complementary than competing. DAST tells you what is wrong with an application you already know about. ASM tells you which applications exist. If you are running one without the other, the gap is usually on the inventory side.
Sources: Invicti pricing and Invicti Web + API, checked September, 2026.
UpGuard and SecurityScorecard
Best for: organisations evaluating third-party risk, vendor security or external exposure monitoring as distinct buying needs.
Both vendors cover third-party risk, but UpGuard also offers Breach Risk for first-party external attack surface monitoring and threat intelligence. SecurityScorecard sells scorecards for monitored organisations, questionnaire management and a vendor system of record, across Free, TITAN and TITAN MAX tiers with Core, Premium and Elite packages. UpGuard covers Vendor Risk, Breach Risk and Trust Exchange. SecurityScorecard does not show plan amounts on its pricing page; UpGuard publishes Trust Exchange at $0/month and $600/month billed annually, plus Vendor Risk from $1,750 per month billed annually, with other plans on request.
Where we differ. We assess your own assets, after you have proved you control them - which is, by design, the opposite of how third-party risk assessment has to work. If your question is about suppliers, these are the right category and this is the wrong page.
Sources: SecurityScorecard pricing, UpGuard Vendor Risk pricing, UpGuard Breach Risk pricing and UpGuard Trust Exchange pricing, checked September, 2026.
Open source options
Best for: anyone who would rather spend engineering time than budget, and has the engineering time.
The open-source tooling in this space is genuinely excellent. subfinder and amass enumerate subdomains, httpx probes what is alive, nuclei runs templated vulnerability checks, and testssl.sh produces TLS assessment that a security engineer can read and trust. All of it is free and none of it is a toy.
We should be straight about something here: AYAsec's TLS assessment is built on testssl.sh. We say so deliberately. It means the output is not a black box - an engineer who wants to check our result can run the same tool against the same host and compare. In a category full of proprietary scoring, being verifiable is worth more than being mysterious.
Where a product earns its price. Not in the scanning, which these tools do well. It is in everything around it: keeping the inventory current, storing results so you can compare this month with last, noticing that a grade dropped and telling someone, producing a report a non-engineer can read, and keeping all of that running when the person who set it up is on holiday.
If you have someone who enjoys maintaining that pipeline, build it - you will end up with something well fitted to you. If nobody does, that pipeline quietly stops running about four months in, and an unmaintained scanner is worse than none because it looks like coverage.
How to choose
If you have no dedicated security team
You need a complete inventory and a short list of what to fix first, not a platform to administer. Look for import from your own DNS, a result on the first day, and findings that explain themselves. Ignore feature counts.
If you are an MSP or MSSP managing several clients
The deciding factors are client separation, per-client reporting and access control. Ask whether each client can be isolated, whether reports can be produced per client, and whether pricing punishes you for adding clients - per-asset pricing usually does.
If you need third-party risk rather than your own surface
If the question is "how secure are our suppliers", this is the wrong page. That is security ratings and vendor risk management, a different category with different tools. AYAsec assesses your own assets, after you prove you control them, which by design is not how vendor risk works.
If you need deep web application testing
An ASM tool finds the application and checks its configuration. It does not replace authenticated, application-aware testing. If that is your priority, buy for that and treat ASM as the layer that tells you what to point it at.
When AYAsec is not the right fit
Said plainly, because a list that recommends its author for everything is worth nothing:
- Internal networks. AYAsec looks from the outside. Anything behind the corporate perimeter is out of scope.
- Cloud posture management. Misconfigured storage buckets and IAM policies are a different problem.
- Deep application security testing. The HTTP scan uses OWASP ZAP and finds a great deal, but it is not a substitute for a dedicated application security programme.
- Compliance attestation. You get findings, grades and evidence; you do not get a certificate.
- You want a result in ten seconds on a domain you do not control. Ownership verification exists precisely to prevent that.
Frequently asked questions
What is the difference between ASM and vulnerability management?
ASM works out what you expose to the internet. Vulnerability management works out what is wrong with the assets you already know about. ASM is how you find out whether that list is complete.
Do I need both?
Most organizations end up with both. The order matters: an incomplete inventory makes everything downstream incomplete too.
How much should this cost?
It depends less on the number than on the model. Among the tools here, Attaxion and Detectify charge by asset, Intruder charges a base fee plus per target, ProjectDiscovery sets fees through an order form, Tenable sells a licence, and AYAsec charges a flat fee per organization. Asset-based models have an awkward property: the bill grows as discovery works, and discovering more is the point. Whichever you choose, ask the same question - what happens to the price when we add fifty subdomains?
Note also that six of the eleven tools on this page publish plan prices and five do not. That is not a judgement, but it does tell you how much of the evaluation you can do before talking to someone.
How long does setup take?
Ask specifically how long until the first report. Some tools are minutes; others need an onboarding call before anything runs.
Which is best for an MSSP?
Whichever separates clients properly and does not charge per asset. Test both with two real clients before committing.
If you want to see your own attack surface before comparing anything further,
start with the attack surface management guide or run a scan on your own domain.