Fraud Prevention API Comparison 2026:
IPASIS vs IPQS vs MaxMind vs Sift vs Others

The online fraud prevention market is projected to reach $40 billion by 2027. With credential stuffing attacks increasing 300% year-over-year and card-not-present fraud driving billions in chargebacks, choosing the right fraud prevention API is no longer optional—it's existential.

But here's the problem: the market is bifurcated. Enterprise solutions like Sift Science (valued at $1.3B after raising $307M) require six-figure contracts and weeks of integration. Meanwhile, small e-commerce shops and indie SaaS builders are stuck with either inadequate free tiers or pay-per-query models that become prohibitively expensive at scale.

This guide provides a technical comparison of the leading fraud prevention APIs, evaluating them on the metrics that actually matter: pricing transparency, API latency, free tier generosity, and integration complexity. We analyzed IPASIS, IPQualityScore (IPQS), MaxMind, Sift Science, proxycheck.io, and FraudGuard.io.

Who Should Use What? A Decision Framework

Before diving into individual providers, here's the landscape:

• Enterprise ($10K+/mo budget): Sift Science if you need machine learning models trained on your data and can dedicate engineering resources to multi-week integrations.
• High-volume scale (1M+ queries/mo): FraudGuard.io offers the best per-query economics, but lacks email validation and trust scoring.
• Small-to-mid market (SaaS, e-commerce, gaming): IPASIS and IPQS compete here. IPASIS wins on free tier generosity (28x more daily requests), single-number trust scores, and sub-20ms latency.
• Proxy detection only: proxycheck.io is cheap but limited. No email validation, no composite trust score.

The Market Gap: Why Small Teams Are Underserved

Most fraud prevention vendors optimize for one of two extremes:

• Enterprise-first pricing: Sift starts at ~$500/month but typically runs $2-10K/mo. Integration requires dedicated engineering time (2-4 weeks) and often a solutions engineer from their side.
• Volume-based pay-per-query: MaxMind charges $0.005-$0.02 per lookup. This seems cheap until you're processing 100K requests/day and paying $1,500-$6,000/month.

The underserved segment: Shopify merchants doing $50K-500K/month, indie SaaS with 1,000-10,000 users, and gaming/gambling platforms that need real-time decisioning but can't justify enterprise contracts.

This is where IPASIS is positioned—generous free tier (1,000 requests/day), flat-rate pricing, and API-first design that takes 5 minutes to integrate.

Individual Provider Breakdown

1. IPQualityScore (IPQS) — Closest Direct Competitor

Best for: Teams that need fraud scoring but have low daily volumes.

IPQS is a solid all-in-one fraud prevention API with IP reputation, email validation, and phone verification. Their API returns granular signals (proxy score, VPN probability, abuse velocity) which is useful for custom rule engines.

Pricing:

• Free tier: 35 lookups per DAY
• Paid: Starts at $99/month for 5,000 requests/month (~167 requests/day)
• Effective cost: ~$0.02 per query at entry tier

Technical Strengths:

• Detailed fraud scoring with individual signal breakdowns
• Email/phone validation in addition to IP intelligence
• Historical abuse tracking across their network

Where IPASIS Wins:

• 28x more generous free tier: 1,000/day vs 35/day
• Simpler trust score: One number (0-100) vs parsing multiple signals
• Lower latency: Sub-20ms global response times vs ~50-80ms

2. MaxMind (minFraud) — The Industry Standard

Best for: Organizations that need offline GeoIP databases or are already using MaxMind for geolocation.

MaxMind pioneered the IP intelligence market and remains the default choice for many enterprises. Their minFraud service offers risk scoring, but it's designed for large-scale batch processing, not real-time decision APIs.

Pricing:

• No free tier for fraud detection (only GeoLite2 database)
• $0.005-$0.02 per query depending on volume and service tier
• $60-600/month for 10K-30K queries

Technical Strengths:

• Mature data sets with decades of IP reputation history
• Offline database option for air-gapped environments
• Strong in geolocation accuracy

Where IPASIS Wins:

• 5-10x faster: Sub-20ms API response vs 80-120ms
• Simpler API contract: Single trust score vs raw data dumps that require interpretation
• Predictable pricing: Flat monthly rate vs unpredictable per-query costs
• Modern infrastructure: Edge-cached responses vs centralized API endpoints

3. Sift Science — Enterprise Fraud Platform

Best for: Large enterprises ($10M+ revenue) that need custom machine learning models and can dedicate engineering resources.

Sift is the category leader for enterprise fraud prevention, with $307M in funding and a $1.3B valuation. They don't just provide an API—they offer a full fraud orchestration platform with ML models, case management tools, and dedicated support.

Pricing:

• Entry tier: ~$500/month
• Typical contracts: $2,000-$10,000/month
• Enterprise: Custom pricing (often $50K+/year)

Technical Strengths:

• Machine learning models trained on billions of events
• Full fraud workflow platform (not just an API)
• Account takeover prevention, payment fraud, content abuse
• Dedicated solutions engineers and custom integrations

Where IPASIS Wins:

• 50-100x cheaper: Perfect for teams under $500K ARR
• 5-minute integration: Simple REST API vs weeks of platform setup
• API-first design: Drop-in middleware vs complex SDK instrumentation
• No vendor lock-in: Standard HTTP API vs proprietary platform

4. proxycheck.io — Budget Proxy Detection

Best for: Teams that only need proxy detection and have ultra-tight budgets.

proxycheck.io is a single-purpose API for detecting proxies, VPNs, and datacenter IPs. It's cheap, simple, and reliable for basic use cases.

Pricing:

• Free tier: 1,000 queries/day (same as IPASIS)
• Paid: $3.99/month for 10K queries/month
• Volume discounts available

Technical Strengths:

• Rock-bottom pricing
• Simple, focused API
• Good proxy/VPN detection coverage

Where IPASIS Wins:

• Email validation included: proxycheck.io only does IP analysis
• Interaction Trust Score: Single 0-100 number vs binary yes/no proxy detection
• Fraud-focused features: Abuse velocity, risk scoring, not just proxy detection

5. FraudGuard.io — Best Volume Pricing

Best for: High-volume applications (1M+ queries/month) that only need IP intelligence.

FraudGuard.io offers the most aggressive volume pricing in the market. If you're processing millions of requests, they're hard to beat on cost.

Pricing:

• Free tier: 5,000 queries/month
• Paid: $29/month for 1 million queries
• Effective cost: ~$0.000029 per query

Technical Strengths:

• Unbeatable volume pricing
• Good IP threat intelligence coverage
• Simple REST API

Where IPASIS Wins:

• Combined IP + Email scoring: FraudGuard.io only does IP intelligence
• Single trust score: Simplified decision-making for non-specialists
• Better for small-mid market: Their pricing optimizes for 1M+ queries; IPASIS is better for 10K-500K/month range

Side-by-Side Comparison Table

Use Case Matrix: Which Provider for Your Situation

Small E-commerce (Shopify, WooCommerce) — Revenue: $50K-500K/mo

Recommended: IPASIS

You need real-time fraud screening at checkout but can't justify $500+/month. IPASIS's generous free tier (1,000/day) covers most small shops, and paid plans scale predictably. Integration takes 5 minutes via API or Shopify app.

Indie SaaS Builders — 1,000-10,000 Users

Recommended: IPASIS

You're building fast and need to prevent bot signups and trial abuse without vendor lock-in. IPASIS's single trust score (0-100) means you can gate signups with a simple if (score < 70) check. No complex SDK integration.

Gaming/Gambling Platforms — Real-Time Decisioning

Recommended: IPASIS or proxycheck.io

Sub-20ms latency is critical. IPASIS wins if you need email validation and composite trust scoring. If you only care about detecting VPNs/proxies and have ultra-tight margins, proxycheck.io works.

Enterprise Fintech — $10M+ Revenue, Regulatory Compliance

Recommended: Sift Science or MaxMind

You need audit trails, compliance documentation, and custom ML models. Sift offers the full platform. MaxMind is the fallback if you need offline databases for air-gapped environments.

High-Volume API Services — 1M+ Queries/Month

Recommended: FraudGuard.io

If you're processing millions of requests and only need IP intelligence (not email validation), FraudGuard.io's $29/mo for 1M queries is unbeatable. IPASIS is better if you need combined IP+email scoring.

Why the Free Tier Matters (A Lot)

Free tiers aren't just for testing—they're essential for small teams and side projects that can't budget $100+/month upfront. Here's the math:

• IPASIS: 1,000/day = 30,000/month → covers most sub-10K user SaaS apps
• IPQS: 35/day = 1,050/month → barely covers a single signup flow test
• MaxMind: No free tier → pay from day one

If you're bootstrapping a Shopify app or building a weekend project, IPASIS's free tier gives you production-grade fraud prevention without financial commitment.

The IPASIS Advantage: Built for the 80%

Most fraud prevention vendors optimize for either enterprise contracts (Sift) or high-volume discounts (FraudGuard.io). IPASIS targets the underserved middle market:

• Generous free tier: 1,000 requests/day (28x more than IPQS)
• Single trust score: 0-100 number, not a data dump requiring interpretation
• Sub-20ms latency: Edge-cached responses, globally distributed
• Combined IP + Email: Single API call for complete interaction validation
• 5-minute integration: Drop-in REST API, not a multi-week platform setup

Technical differentiation: IPASIS's Interaction Trust Score aggregates proxy detection, email validity, abuse velocity, and geolocation consistency into a single 0-100 metric. This eliminates the need for custom rule engines—just set your threshold and gate actions accordingly.

Market Trends: Why Residential Proxy Detection is the New Battleground

Five years ago, blocking datacenter IPs (AWS, GCP, Azure) was sufficient. Today, sophisticated attackers use residential proxy networks—legitimate home IPs rented from ISPs or compromised devices. These proxies:

• Cost $15-50/GB on the black market
• Rotate IPs every few minutes via DHCP
• Bypass simple ASN-based blocking

Static blocklists (the approach MaxMind uses for offline databases) can't keep pace. You need real-time intelligence updated continuously as proxy networks evolve. This is where IPASIS, IPQS, and FraudGuard.io have an advantage over offline database vendors.

Conclusion: Choose Based on Your Stage

There's no single "best" fraud prevention API—it depends on your stage, budget, and technical requirements:

• Bootstrapped/small teams: IPASIS (generous free tier, simple integration)
• Mid-market SaaS/e-commerce: IPASIS or IPQS (both solid; IPASIS wins on latency and free tier)
• High-volume (1M+ queries/mo): FraudGuard.io (best per-query pricing)
• Enterprise with budget: Sift Science (full platform, custom ML models)
• Legacy systems needing offline data: MaxMind (offline databases, established reputation)

For the 80% in the middle—teams building real products without enterprise budgets—IPASIS offers the best balance of affordability, performance, and simplicity. The 28x more generous free tier alone makes it worth testing before committing to paid plans elsewhere.