Buyer's guide

The best account takeover detection software, by what you need

Five options, from a single API call to a managed fraud platform. We make LoginLlama, so we've said plainly where each of the others is the better pick. Every price and feature links to its source.

Quick picks

Side by side

ToolFree tierPricingSetup
LoginLlamaYes: 1,000 checks a month, no card.Published. Starter $19 a month for 10,000 checks, Professional $49 for 50,000, Enterprise $199 for unlimited.One API call from your login handler. SDKs for Node, Python and more, an Auth0 Action, a Better Auth plugin and an MCP server.
CastleYes: 1,000 Risk API calls a month, with 3-day data retention.Published. Free at $0, Pro at $200 a month (includes $200 of API usage), Enterprise from $4,000 a month. Risk requests cost $0.005 each.SDK plus console configuration for policies and custom signals.
SiftNone listed.Not published. The site offers a demo request and a call with an expert.Platform integration, arranged through Sift.
Arkose LabsNone listed.Not published. The site directs visitors to schedule a meeting or talk to an expert.Client and server integration with challenges, arranged through Arkose.
Auth0 Attack ProtectionComes with your Auth0 tenant, subject to your plan.Part of Auth0. Which features come with which plan is set by Auth0.Switch each feature on in the Auth0 Dashboard.

The five options

LoginLlama

Best for: Developers who want a login risk score and user alerts today

One API call at login returns a 0 to 10 risk score with reason codes: new device, new location, impossible travel, VPN, Tor and known-bad IPs. When a login comes from a new device, it emails the user a "was this you?" alert in your name.

Pick it when

  • You want to sign up, get a key and score your first login the same day.
  • You want your users told about a new login without building the email yourself.
  • You want a flat monthly price you can read before you talk to anyone.

Source

Castle

Best for: Custom policies and device-level signals

Castle sells risk scoring for bots, abuse and account takeover, plus IP intelligence, device fingerprinting and custom policies.

Pick it when

  • You need device-level signals such as emulator or jailbreak detection.
  • You want to write your own policies and signals.
  • You prefer pay-per-request pricing at very low volume.

Source · LoginLlama vs Castle →

Sift

Best for: Fraud teams that investigate cases

Sift Account Defense detects account takeover by scoring logins on device intelligence, behavioural patterns, unusual account changes and network signals, so teams can allow, challenge or block. It also offers session-level controls, investigation summaries and post-login monitoring.

Pick it when

  • You need post-login monitoring and investigation workflows.
  • You have a fraud team that will use case-management tools.
  • You operate at a scale where a sales-led contract is normal.

Source · LoginLlama vs Sift →

Arkose Labs

Best for: Large-scale bot and AI agent attacks

Arkose Labs sells bot and AI agent defense built around challenges, plus identity and trust products such as Device ID and Email Intelligence. Its solutions include account takeover protection, fake account prevention and SMS toll fraud defense.

Pick it when

  • You face large-scale automated attacks and want challenges that raise the attacker cost.
  • You need protection at sign-up and SMS flows, not only login.
  • You want a vendor that handles bot traffic as a managed service.

Source · LoginLlama vs Arkose Labs →

Auth0 Attack Protection

Best for: Auth0 tenants that need the basics switched on

Auth0's built-in protection: Bot Detection (a CAPTCHA for suspected bots), Suspicious IP Throttling, Brute-Force Protection and Breached Password Detection. It targets password guessing and known-breached passwords.

Pick it when

  • You already use Auth0 and want brute-force and breached-password checks with no code.
  • Your main worry is password guessing, not a correct password used from a stranger's laptop.

Source · Adding login risk scoring to Auth0 →

How to choose

Does the attacker already have the password?

Credential stuffing and phishing hand attackers working passwords. Brute-force limits and breached-password checks do nothing about a correct password. You need something that scores the device, network and location around the login.

Who acts on the result?

A fraud team will use investigation tools and case queues. A product team usually wants a score and a reason it can act on in code: allow, ask for MFA, or block.

Should the user hear about it?

The person who knows whether a login was them is the account owner. An alert on a new device catches the takeover your rules missed, often within minutes.

Can you try it before a sales call?

Published pricing and a free tier let you test on your own traffic. Sales-led tools suit large contracts, and take weeks to evaluate.

New to the problem? Start with how account takeover detection works, or read why 2FA is not enough on its own.

Account takeover detection software FAQ

What is account takeover detection software?

Account takeover detection software scores each login for signs that someone other than the account owner is signing in: a new device, a new country, impossible travel between logins, or a VPN or Tor exit. Your app then allows the login, asks for a second factor, or blocks it.

Do I need account takeover detection if I already have MFA?

MFA stops most password-only attacks, but session theft, MFA fatigue and SIM swaps get past it, and many apps leave MFA optional. Detection tells you which logins are unusual so you can require MFA for those, and tells users when one gets through.

How much does account takeover detection software cost?

Self-serve tools publish prices: LoginLlama runs from a free tier to $199 a month for unlimited checks, and Castle Pro is $200 a month. Sift and Arkose Labs do not publish prices and sell through a sales process.

Does Auth0 have account takeover detection built in?

Auth0 Attack Protection covers bot detection, suspicious IP throttling, brute-force protection and breached passwords. It does not score a correct password used from a new device or location, and it does not alert users to new logins. You can add that with a Post-Login Action.

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