Ad fraud is a major contributor to spam and fake lead generation. But it can affect any kind of paid media advertiser, which is why strong ad fraud detection software is essential. Discover more about ad fraud detection for each major type of ad fraud below.

Ad fraud is a widespread problem for paid media advertisers. When you’re seeing a rise in unresponsive leads, and increased costs with no improvement in results, it’s natural to worry that ad fraud is impacting your PPC efforts.

Ad fraud refers to any fake paid ad interaction designed to extract money or unfairly compromise results for the legitimate advertiser. It’s a fairly broad category that covers click fraud, impression fraud, domain stacking, and other types of invalid traffic (IVT).

According to Lunio’s 2026 Global Invalid Traffic Report, $63 billion was lost to invalid traffic in 2025. And this is just one part of the problem — ad fraud encompasses all types of paid media fraud, so the real costs are likely far higher.

In this guide to ad fraud detection, you’ll discover the most impactful types of ad fraud, what ad fraud can look like in Google and Meta campaigns, and which tools are best for detecting each major type of ad fraud.

What is ad fraud?

Ad fraud refers to any fake activity that extracts money from a legitimate advertiser by generating a false interaction with a paid ad. Impressions, clicks, app installs, and conversions can all be affected by ad fraud.

Ad fraud is usually committed by ad publishers, click farms, botnets, affiliates, or (less often) competitors. They profit from the fraudulent activity at the expense of the legitimate advertiser.

The types of ad fraud

Learn about the most common types of ad fraud in the table below.

Lunio’s click fraud calculator estimates how much of your ad budget you’re losing to click fraud. Enter your ad platform, monthly budget, and industry below to see your estimate:

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Click Fraud Calculator Click fraud takes 7–15% of every ad budget. Find out yours.

60 seconds, no signup. Built on Lunio's analysis of 2.7B+ ad clicks. Find out your industry's invalid traffic rate, your wasted spend, and the revenue you could recover.

Step 1 of 3

Start with the basics.

Primary ad platform

Google Meta Microsoft Ads X / Twitter LinkedIn TikTok

Monthly ad spend on this platform

$

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Step 2 of 3

Pick your industry & CPC.

Your industry

Retail6.03% IVT Software & IT6.48% IVT Cybersecurity7.90% IVT B2B SaaS8.20% IVT Luxury Retail8.60% IVT Travel9.04% IVT Finance & Insurance10.12% IVT Healthcare & Pharma10.80% IVT Automotive11.20% IVT Legal Services11.40% IVT Home Services12.80% IVT Recruitment & HR13.20% IVT Real Estate13.61% IVT Telecoms & Utilities14.26% IVT Education14.41% IVT Gaming & iGaming18.49% IVT

Your average CPC (we'll pre-fill an industry estimate)

$

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Industry · Platform · $0 annual spend

Click fraud is taking $0

from your business every year. That's $0 every month walking out the door — and another $0 every day you don't act.

Invalid clicks / yr

0

Wasted ad spend

$0

Invalid traffic

0%

Google won't fix this. Lunio will.

Run a free 14-day audit on your live account and see your real numbers — broken down by campaign, keyword, geo and domain.

✓Your actual IVT rate ✓Top wasted-spend sources ✓Recoverable revenue

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↗ After activation, Lunio customers see avg 13% higher on-page CVR and 7% lower CPL. Trusted by 1,400+ brands · 4.7 on G2.

Recalculate with different inputs

Calculations based on Lunio's Global Invalid Traffic Report 2026. Eight industries shown use Lunio-measured rates; additional industries use Lunio-methodology estimates calibrated against comparable verticals. Lost revenue applies Lunio's conservative 3:1 ROAS baseline — every $1 of wasted ad spend equals roughly $3 in missed revenue. Actual results vary by account.

Why ad fraud is a lead quality problem

Any kind of ad fraud can be damaging. But when it starts to affect your sales pipeline, it’s even more insidious.

For example: a new lead lands in your CRM. Attribution shows the lead came from an automated PPC campaign. You pass the lead to your sales team to follow up. After several failed attempts to contact them, sales chalks it up as a spam lead and passes it back to you.

In the meantime, the fake click has polluted your analytics, making your data unreliable. Chasing the fake conversion has wasted your sales team’s time. And the conversion signal has taught your automated campaign to look for more invalid clicks just like it.

So even though the wasted ad spend is frustrating, the impact can spiral far beyond this. Lunio data from 2026 shows that lead gen businesses experience 32.07% higher invalid traffic rates than transactional advertisers. And costs like wasted sales time and damaged pipeline quality often go unmeasured — so the cost of invalid traffic is likely much higher than it seems.

Lead gen advertiser Culligan Harvey began using Lunio after seeing a sharp rise in low quality leads from their paid media campaigns. Within the first month, they saw a huge 42% increase in lead to demo conversions, reflecting the significant reduction in invalid traffic.

Ad fraud in Google Ads

Google does more than most other ad platforms to tackle ad fraud, but it’s still nowhere near enough to properly counter the problem. Google recognizes some invalid traffic — usually benign bots and other general IVT — but allows the most sophisticated IVT to filter through.

Where Google recognizes click fraud, it offers ad credits (rather than Google Ads refunds) you can put towards future campaigns. But post-click IVT recognition does nothing to tackle the impact on automated campaign signals. When algorithms start to seek out more users based on existing invalid traffic, more of your budget gets eaten by fraudulent clicks.

Additionally, Google Display Network and partner placements are prone to very high rates of IVT. The average IVT rate for GDN is 12.02%, compared with 5.21% in Google Search. Google Video Partner advertisers are exposed to an average IVT rate of 20.62%. So more than a fifth of GVP traffic could be fraudulent.

Ad fraud in Meta Ads

Meta ads are exposed to even higher volumes of IVT than Google ads, leading to higher rates of click fraud on Meta ads. We found an average IVT rate of 8.20% across Meta channels, compared with 7.57% in Google.

Like Google, Meta places ads across partner sites via its Audience Network. Transparency across these placements is relatively limited, which means your ads could be served on MFA websites and other dodgy inventory without you realizing.

Plus, Meta Advantage+ advertisers have limited control over placement selection, and excluded placements can still receive up to 5% of spend. So it’s much harder to control where your Meta ads are shown.

Meta also has built-in lead forms, which can be exploited by fraudsters and filled by bots or other fake users.

Meta is doing very little to tackle the problem, considering its scale. Automated systems only ban advertisers if they’re at least 95% certain they’re committing fraud — so many scams are likely slipping through these rudimentary filters.

How ad fraud detection works

Ad fraud detection and click fraud detection start with vigilant monitoring techniques, such as:

• IP and network signal analysis — User signatures are mapped to existing data to flag known bots or IVT. This is a fast way to eliminate GIVT and benign bots, as well as known botnets, but it’s not very effective against more sophisticated IVT.
• Device and environment analysis — Ad fraud detection tools build digital fingerprints based on device and environment data. Device fingerprinting helps identify devices to improve UX for real users, while weeding out a certain level of IVT. But advanced bots can spoof device fingerprints.
• Cross-channel signals — Information from multiple ad channels is combined to identify IVT across your broader paid media infrastructure.

Ad fraud detection is becoming more difficult. AI bot traffic can increasingly emulate real human users. So manual ad fraud detection measures aren’t always enough to tackle the problem.

While it’s possible to spot patterns in conversion rates, engagement, locations, and source repetition manually, these tactics don’t work at scale. Residential proxies can limit the effectiveness of IP blocking. And Google only gives advertisers a 500 IP exclusion limit, which many advertisers reach quickly.

The most advanced tools use behavioral analysis powered by machine learning to detect ad fraud. Machine learning models identify sophisticated and unknown bots based on anomalies that deviate from genuine human behavior, eliminating them from your traffic before they interact with your ads. That’s why effective ad fraud detection needs dedicated tools for the job.

Ad fraud detection tools: Which category solves your problem?

There are three major types of ad fraud detection software, and each solves a distinct problem. Here, we explore each of these ad fraud detection tools and who they work for, so you can decide which solution you need to tackle ad fraud in your paid media campaigns.

Programmatic and media verification tools

Programmatic and media verification tools help control where your ads are served, so you don’t end up paying for non-existent impressions or low-value placements. They offer features like impression quality measurement, viewability verification, and pre-bid filtering across programmatic inventory, as well as video and connected TV environments.

Examples of programmatic and media verification tools include:

• DoubleVerify
• IAS (Integral Ads Science)
• HUMAN

These tools help advertisers improve the quality of media they buy, and scale their programmatic efforts without increasing their exposure to ad fraud.

Advertiser-side paid media protection tools

Click fraud solutions help mitigate fake interactions across paid search, social, and display ads. Using a combination of rules-based filters and machine learning-powered behavioral analysis, these tools minimize click fraud and reduce the knock-on impact on lead quality and campaign performance.

Advertiser-side paid media protection tools include:

• Lunio
• CHEQ
• TrafficGuard

The best click fraud prevention tools eliminate IVT before the click, keeping your data clean for accurate reporting and optimal automated campaign performance. They’re best suited for paid media advertisers running paid search and social campaigns.

Mobile measurement and app fraud tools

Mobile measurement partners offer features like user acquisition tracking and attribution tools, so mobile advertisers can get an accurate picture of their campaign success. But they also detect fake installs and click injection techniques that affect mobile advertisers.

Some of the best-known mobile measurement and app fraud tools include:

• AppsFlyer
• Branch
• Adjust

These tools are best suited to advertisers running mobile app install ads. They can help you monitor performance and reduce the risk of mobile ad fraud.

Many advertisers seek out tools with specific certifications, such as Media Rating Council accreditation or IAB Tech Lab membership. These accreditations are valuable, but it’s not the same as having the right tool for the job. A programmatic verification tool won’t fix lead quality, and a mobile measurement partner won’t audit programmatic inventory.

If you’re looking to tackle click fraud, use our click fraud detection tool comparison to explore the key features and benefits of each top tool, so you can decide which is right for you.

How Lunio detects ad fraud

Manual ad fraud detection is no longer efficient. It’s labor intensive, and the most sophisticated IVT can circumvent these methods anyway. Strong ad fraud detection and prevention requires an automated approach that outpaces IVT technology.

Lunio combines rules-based filters with advanced behavioral analysis techniques to automatically detect invalid traffic and block invalid clicks. It monitors 100% of your paid traffic and validates it in real-time. Invalid users are blocked before they can interact with your ads, keeping your data clean and protecting your budget.

Cleaner conversion data means better signals for automated bid strategies, too — so only genuine leads funnel through to your sales team.

Lunio is built for performance marketers. Setup is easy, with no need for IT or cybersecurity support. And users get built-in reports you can segment by campaign, keyword, location, and domain, giving you genuinely insightful analytics.

Get a free 14-day traffic audit from Lunio and discover how much IVT is affecting your paid media campaigns.

FAQs

Discover more about ad fraud detection in these frequently asked questions.

1. What is ad fraud detection?

Ad fraud detection is the process of identifying fraudulent activity affecting your paid ads. Ad fraud takes lots of different forms, including click fraud, impression fraud, domain stacking, cookie stuffing, and affiliate fraud. So there are also different categories of ad fraud detection that are designed to tackle different kinds of ad fraud.

2. How does ad fraud detection work?

Ad fraud detection platforms use a variety of methods to identify fraudulent activity, including IP, network, and channel signals, device fingerprinting, and behavioral analysis. These techniques combine to block known and basic bots, as well as uncovering new and sophisticated IVT.

3. What is the difference between ad fraud and click fraud?

Click fraud is a type of ad fraud. Click fraud refers specifically to activity designed to drain PPC budgets with fraudulent clicks. Ad fraud, meanwhile, refers to a much broader range of fraudulent activity that includes click fraud, ad stacking, attribution fraud, affiliate fraud, lead gen fraud, and more.

4. What are the main types of ad fraud?

Ad fraud can affect every stage of the sales cycle, thanks to the myriad types of ad fraud out there. The main types of ad fraud include:

• Impression fraud
• Ad stacking
• Pixel stuffing
• Domain spoofing
• Made-for-advertising sites
• Click fraud
• Botnet traffic
• Competitor clicks
• Scraper and crawler clicks
• Click injection
• Click flooding
• SDK spoofing
• Attribution fraud
• Lead gen fraud
• Affiliate commission fraud
• Cookie stuffing
• Retargeting list pollution

Each type of fraud is designed to target a subset of advertisers and involves specific tactics.

5. Is click fraud the same as invalid traffic?

Click fraud and invalid traffic aren’t exactly the same, though they’re sometimes used interchangeably.

Invalid traffic refers to any type of non-human internet user, including benign bots like SEO crawlers, as well as bots used to commit click fraud. Click fraud is the specific act of using IVT to drain an advertiser’s budget via fake clicks.

6. What tools detect fraud on paid ads?

There are three main types of tools used to detect ad fraud:

• Programmatic and media verification tools — best for video and connected TV advertisers
• Advertiser-side paid media protection tools — best for paid search and social advertisers
• Mobile measurement and app fraud tools — best for mobile advertisers

Each tool offers distinct benefits for specific advertisers, so it’s important to find the right tool to protect your ads.

7. Can I detect ad fraud without a tool?

To an extent, yes. But manual click fraud detection is time consuming, labor intensive, and unlikely to capture the more sophisticated types of ad fraud.

Sophisticated invalid traffic is good at mimicking human activity, so it’s more likely to evade standard IP filters and other manual ad fraud detection methods. That’s why third-party traffic verification tools like Lunio use advanced behavioral analysis techniques to accurately detect these problematic types of IVT.

8. Do Google and Meta detect ad fraud themselves?

Google and Meta detect a certain proportion of invalid activity, though their in-platform filters aren’t very effective. A lot of the more sophisticated IVT escapes detection by Google and Meta, so it can still impact your ads.

Additionally, in-platform filters only detect invalid activity after the click. So any identified IVT has already polluted your data and analytics, compromising future performance. That’s why it’s recommended to use an independent ad fraud detection platform, rather than relying on built-in filters.

9. How does AI Max change the risk of ad fraud?

According to Lunio data, AI Max can significantly increase your IVT rate. Our account analysis found a 35% increase in IVT on campaigns using AI Max, compared with those using standard Search.

10. How much of my ad budget is lost to ad fraud?

The average IVT across all industries is 8.51%. But the IVT rate is much higher in certain industries and ad channels. At 24.20%, TikTok has the highest average IVT rate of all channels, while gaming and iGaming are the highest risk industries, with an average IVT rate of 18.49%.

Use Lunio’s click fraud cost calculator to get a strong estimate of how much of your ad budget could be wasted on ad fraud.

11. What is the best ad fraud detection tool?

There’s no single answer here; the best ad fraud detection tool depends on what type of ads you run and the type of ad fraud you’re experiencing.

If your ads are affected by click fraud, compare the best click fraud detection tools to find the right solution to protect your paid media ads.