SAML vs. LDAP: How to Choose The Right Protocol

Are you deciding between SAML and LDAP? If you’re dealing with identity management, these two names always come up — and they often get confused. 

The truth? They’re not interchangeable. 

While they’re both used to share information securely, SAML focuses purely on authentication information. Still, LDAP covers both authentication and broader directory resource information (e.g., printers and servers on a network).

This guide will clear up the confusion and help you decide when and how to use each. We’ll walk you through:

• What SAML and LDAP actually do
• Strengths and weaknesses of SAML vs LDAP
• When to use each one (or both!)
• How they can work together for efficient identity management

Let’s get started.

SAML vs LDAP: Which protocol should you use?

Here’s the TL;DR about which protocol to choose: 

• Use SAML if you have a cloud-based SaaS app into which you want to control access and authorization with Single Sign-on (SSO).
• Use LDAP if you are deploying software on-premises and behind a firewall and want the most straightforward authentication method or want users to access local network resources specifically. 
• Use SAML and LDAP if you need the best of both worlds. For example, IdPs can use LDAP to retrieve user data necessary for SAML-based authentication.

Read more:

• What is SAML and how does it work?

• WorkOS: SSO done for you

What is SAML?

Security Assertion Markup Language (SAML) is a standardized protocol for exchanging authentication data between the identity provider (like Okta or Ping) and the service provider (your SaaS app, for example). 

SAML works via the exchange of assertions — XML-based documents packed with user authentication and authorization details like identity, permissions, and profile attributes (e.g., email address).

This exchange lets users sign in to multiple applications using a single login session, or Single Sign-On (SSO).

Here’s a quick breakdown of the process:

1. The user tries to access a service. The service provider redirects them to the identity provider.
2. The identity provider verifies the user’s credentials and creates a SAML assertion with their details.
3. The assertion goes back to the service provider, which validates it and logs the user in.

What SAML is great at

• Widely supported and well-documented: SAML is well-documented and widely supported with various pre-made libraries and integrations, making it relatively straightforward to implement across significant identity providers.
• Ideal for cross-domain authentication: Unlike LDAP, which is optimized for working within a single domain (e.g., a single enterprise company), SAML is specifically designed for federated environments. This is particularly useful for SaaS applications needing authentication across corporate domains.
• Broad compatibility across IdPs: SAML works seamlessly with major identity providers, enabling you to reuse a single implementation across multiple IdPs. While occasional adjustments — like attribute mapping or metadata tweaks — might be needed for specific configurations, these are usually minimal compared to implementing from scratch.

What SAML is not so great at

• It’s not a directory protocol: SAML is designed purely for authentication and doesn’t handle directory management like LDAP.
• It’s not a real-time protocol: SAML handles authentication only when logged in. Changes to user access, like revocations, won’t take effect until the user logs in. This gap can pose risks for sensitive data but can be mitigated when paired with SCIM provisioning.

What is LDAP?

LDAP, or Lightweight Directory Access Protocol, is a protocol for accessing and managing directory services. Think of it as a central directory that stores everything from employee account details to network resources like printers and file shares, even to physical devices like laptops and phones.

Here’s how it works: LDAP servers host this directory information, and LDAP clients connect to them over a TCP/IP network to perform actions like searching for specific entries, adding new ones, or updating existing records. For example, an employee using a desktop computer might use LDAP under the hood to connect to the nearby office printer.

While LDAP’s primary focus is managing resources on a local network, it also has built-in authentication capabilities to allow secure access to these resources. This means that LDAP can function as an intermediary identity provider service between an app and an IdP like Microsoft Entra ID (formerly Microsoft Active Directory). LDAP securely verifies user credentials and provides the app with authentication and authorization data.

What LDAP is great at

• Wider access to directory services: Unlike SAML, which is broadly “just” an authentication protocol, LDAP has a much broader scope and can perform CRUD-style actions on directory entries.
• On-premises support: LDAP is specifically designed for environments where a directory service, like Microsoft Entra ID, is running on-premises, unlike SAML, which is better suited for cloud-based apps.
• Ideal for legacy systems: LDAP has existed since the early ’90s. It’s reliable and extensively supported, and it is usually used for enterprise setups that rely on older, on-premise systems. 

What LDAP is not so great at

• Cross-domain authentication and access: LDAP wasn’t built for the modern web. It’s not browser-friendly, lacks token-based authentication, and is usually associated with a single directory. 
• It’s difficult to implement compared to SAML: LDAP’s age shows when it comes to implementation. Unlike SAML’s standardized approach, LDAP requires more steps, like setting up a client-server architecture and dealing with schema design. Its adoption on modern platforms like Node.js is minimal, making it harder to work with in newer environments.

What can you use SAML and LDAP for?

Despite their differences, SAML and LDAP share a few everyday use cases:

• Authentication: Both protocols let you verify user credentials and determine access levels from a central source.
• Single Sign-On: Each protocol can enable users to log in once and access multiple apps or services without reauthenticating.
• Secure resource access: Both support granular access control for systems or physical resources, like shared printers or sensitive databases.

SAML excels in cross-domain authentication, while LDAP focuses on secure access to local resources.

Frequently asked questions

Can you use SAML and LDAP together?

Yes. LDAP can complement SAML by providing directory information that an IdP uses to authenticate users, thus bridging the gap between your app and a directory service like Microsoft Entra or Okta. For example, an enterprise might configure its LDAP server to handle this role instead of relying on external IdPs.

Which is better, LDAP or SAML?

SAML is your go-to if you’re managing access for a cloud-based app and need SSO across multiple identity providers. It has built-in security, web and browser compatibility, and ubiquitous support from major corporate identity providers.

 But LDAP is the better choice if you’re working on-premises and need straightforward access to local network resources.

Ultimately, these protocols are not directly comparable — what you use depends on the problem you’re trying to solve.

LDAP vs SSO: What’s the difference?

LDAP and SSO serve different purposes but can work hand-in-hand. 

SSO allows users to log in once and access multiple services, typically using protocols like SAML. LDAP, on the other hand, handles authentication directly with a directory service, verifying credentials and providing access rights. For example, in an SSO flow, LDAP might authenticate a user against the directory during the initial login and then inform SAML about the user's access rights.

That said, LDAP and SSO don’t depend on each other and can function independently. LDAP is not a prerequisite for SSO, and vice versa, as SSO can be achieved using protocols like SAML and OIDC. These two concepts can work together to provide a comprehensive identity management solution, but each can be implemented independently to address specific authentication and authorization needs. 

LDAP vs SCIM: What’s the difference?

LDAP is a directory service protocol used to access and query user data. It doesn’t really handle the full lifecycle of users — things like creating, updating, or deleting accounts aren’t standardized across services. It provides a way to look up and retrieve information about existing accounts.

SCIM is designed to manage the entire user lifecycle across services — creating, updating, and deleting accounts. It's about standardizing how user data is transferred between systems (usually an IdP and an SP).

Try an easier integration with WorkOS

Choosing the right protocol is critical for meeting your enterprise customers’ needs, but managing integrations for every IdP can quickly become overwhelming. 

Instead of navigating the complexities of SAML, LDAP, and other protocols, let WorkOS handle the heavy lifting. With a single API-based integration, you can connect to all major IdPs in minutes and focus on building your core product.

• Get started fast: With SDKs for every popular platform and Slack-based support, you can implement SSO in minutes rather than weeks.
• Avoid the back-and-forth: WorkOS’ Admin Portal takes the pain out of onboarding your customers’ IT teams and configuring your app to work with their identity provider.
• Pricing that makes sense: Unlike competitors who price by monthly active users, WorkOS charges a flat rate for each company you onboard — whether they bring 10 or 10,000 users to your app.

Explore Unified SSO by WorkOS.