Graph databases are purpose-built for understanding complex relationships between data, making them essential for modern applications like fraud detection, cybersecurity, supply chain management, and more.

JanusGraph is a well-known open-source solution in this space, praised for its scalability and backend flexibility. It's designed for large-scale deployments and supports various pluggable components like Apache Cassandra, HBase, and Elasticsearch. However, JanusGraph isn’t always the best fit. It requires managing multiple distributed systems, configuring complex schemas, and tuning performance across multiple layers. For many teams, that trade-off means high operational overhead.

Fortunately, a number of strong alternatives exist in 2025: some prioritize ease of use, some are fully managed, and others deliver specialized performance for analytics or real time applications. Whether you’re building a cloud native application, looking for a more developer friendly interface, or want to skip the burden of running distributed storage, it’s worth considering what other platforms offer. 

In this guide, we’ll break down how JanusGraph works, why some teams look beyond it, and introduce five top alternatives, including PuppyGraph, Neo4j, Amazon Neptune, TigerGraph and Nebula, so you can choose the graph database that fits your technical and operational needs.

What is JanusGraph?

JanusGraph is an open-source, distributed graph database optimized for storing and querying large-scale graph data. It was originally forked from the Titan graph database project, which was developed by Aurelius and later acquired by DataStax in 2015. After Titan became inactive, the open-source community, supported by companies like IBM and Google, launched JanusGraph in early 2017 under the Linux Foundation. Since then, it has evolved into a stable and flexible solution for teams building complex graph applications at scale.

Unlike many graph databases that bundle storage and compute into a single system, JanusGraph uses a modular architecture. It acts as a graph engine that connects to backend components for data storage (such as Apache Cassandra or HBase) and indexing (like Elasticsearch or Apache Solr). This decoupled model gives users more control over infrastructure and allows for horizontal scaling using well-known, battle-tested technologies.

JanusGraph supports Apache TinkerPop, the leading open-source framework for graph computing, and uses Gremlin as its query language. It's a transactional system that supports ACID guarantees with consistency options ranging from strong to eventual, depending on the backend configuration. JanusGraph is built to handle thousands of concurrent users performing complex graph traversals in real time.

In addition to online transactional processing (OLTP), JanusGraph also supports global graph analytics (OLAP) through integration with Apache Spark. This allows teams to run large-scale batch computations across the graph, such as centrality scoring, community detection, or influence propagation, using the same underlying data.

With schema customization, flexible backend support, and integration into broader data ecosystems, JanusGraph provides a powerful foundation for organizations that need to build graph solutions at scale, so long as they are prepared to manage the operational complexity that comes with it.

How does JanusGraph work

At a high level, JanusGraph processes graph queries by translating them into operations across a distributed infrastructure. When a user submits a traversal using Gremlin, JanusGraph interprets that query and orchestrates reads, filters, and joins across its connected backend systems. It encodes graph data (vertices, edges, and their properties), into a form suitable for distributed storage, and uses external indexing systems to accelerate lookups on properties or edge labels.

JanusGraph itself does not persist or index data directly. Instead, it defines how graph structures are represented and executed, while delegating persistence to a storage backend (like Cassandra or HBase) and search to an indexing backend (like Elasticsearch or Solr). This separation of concerns gives users flexibility in system design and scalability, but also requires managing multiple components together.

The system is built around the property graph model and supports transactional workloads, concurrent access, and analytics workflows. Each part of the architecture, from data modeling to execution and storage, can be customized or extended, making JanusGraph a highly adaptable but complex platform.

Modular and Pluggable Architecture

JanusGraph is designed as a modular and extensible graph platform. It handles the graph model, schema, and traversal execution, but relies on external systems for data persistence, indexing, analytics, and more. This flexibility allows users to tailor JanusGraph to a wide range of infrastructure environments and performance needs.

For graph storage, JanusGraph delegates to distributed storage backends such as Apache Cassandra, HBase, or Google Bigtable. These systems store the encoded graph structure, vertices, edges, and properties, across a scalable and fault-tolerant architecture.

For property indexing, JanusGraph connects to indexing backends like Elasticsearch, Solr, or Lucene. These indexes support fast property lookups, filtering, and full-text search capabilities that complement JanusGraph’s traversal engine.

Beyond storage and indexing, JanusGraph can also integrate with:

• Graph analytics engines such as Apache Spark, using TinkerPop’s OLAP GraphComputer interface for large-scale, batch-based graph computations.
  
  
• Visualization tools and export formats for interactive graph exploration or external processing.
  
  
• Custom plugins for caching, authentication, or external system integration.

This modular architecture gives teams significant freedom to design a graph processing stack that fits their exact requirements—but also requires them to assemble, configure, and maintain multiple moving parts.

Physical Storage and the Property Graph Model

JanusGraph uses the property graph model, where vertices and edges can both have properties (key-value pairs). For example, a User node might have properties like email, department, and created_at, while an edge like HAS_ACCESS could carry granted_by and expires_on.

Internally, JanusGraph encodes this data into adjacency list–like records. It organizes relationships around each vertex, preserving edge direction, labels, and connection metadata. These records are passed to external storage backends such as Cassandra or HBase for persistence and partitioning.

By storing connections alongside each node and using local adjacency, JanusGraph supports efficient traversals even in dense, highly connected graphs.

Query Execution with Gremlin

JanusGraph uses Gremlin, the traversal-based query language from Apache TinkerPop. Gremlin allows users to describe complex paths through the graph, such as multi-step relationships, recursive dependencies, or neighborhood aggregations. Gremlin’s expressiveness makes it suitable for querying both direct relationships (e.g., "which users follow Alice?") and complex chains (e.g., "which developers have indirect access to a sensitive system via inherited roles?").

In OLTP mode, queries are executed interactively on live data. JanusGraph compiles Gremlin traversals into logical steps, then maps those steps to backend operations, combining storage reads, index lookups, and adjacency resolution.

In addition to real-time queries, JanusGraph also supports large-scale graph analytics. By integrating with tools like Apache Spark, it can run batch computations across the entire graph, such as PageRank, community detection, or shortest path analysis. These operations are useful when you need to understand the global structure of the graph or run data science workflows on top of it.

This capability allows JanusGraph to handle both interactive graph traversals and deeper analytical workloads, making it suitable for teams that need flexibility across real-time and offline use cases.

Transactions and Consistency

JanusGraph is a transactional database that supports ACID semantics for real-time (OLTP) workloads. Each transaction is isolated and atomic, with optional durability guarantees depending on the configuration of the storage backend.

In distributed environments, JanusGraph supports both strong and eventual consistency models. For example, Cassandra allows tuning consistency per operation, enabling a balance between performance and data guarantees.

JanusGraph also handles concurrent access from thousands of users and supports lightweight locking to manage write conflicts. Combined with transactional support, this enables safe concurrent graph updates without data corruption or race conditions.

Why explore JanusGraph alternatives?

JanusGraph offers a flexible and powerful foundation for building graph-powered applications at scale. Its modular architecture and support for both OLTP and OLAP workloads make it attractive for teams with specific infrastructure preferences or legacy requirements. But for many users, this flexibility comes with trade-offs.

First, operating JanusGraph typically means managing multiple systems, at a minimum, a storage backend and an indexing backend. Configuring, scaling, and tuning these components requires a deep understanding of distributed systems. Even small misalignments between them can impact query performance or data consistency.

Second, while Gremlin is expressive, it has a steep learning curve and can feel unintuitive for teams coming from SQL or Cypher. Debugging complex traversals or reasoning about performance can take time, especially as data volumes grow.

Third, JanusGraph doesn't provide a native cloud offering or a self-contained deployment model. Organizations looking for managed services, faster setup, or a simplified architecture may find better fits elsewhere, particularly for workloads that don't require fine grained backend control.

Finally, use cases have shifted. Many modern graph applications don’t start with dedicated graph databases at all. Instead, teams want to query existing relational data as a graph, or work with cloud-native tools that minimize infrastructure overhead.

For those reasons, it’s worth exploring what other platforms offer, whether you need something easier to operate, faster to deploy, or more aligned with your existing stack.

Top 5 JanusGraph Alternatives

In this section, we’ll walk through five of the most notable JanusGraph alternatives in 2025. Each one takes a different approach to graph processing, from native graph databases to real-time engines that work directly on relational data. We’ll explore how they compare in terms of architecture, use cases, and the kinds of teams they best serve.

PuppyGraph

PuppyGraph is the first and only real time, zero-ETL graph query engine in the market, empowering data teams to query existing relational data stores as a unified graph model that deployed in under 10 minutes, bypassing traditional graph databases' cost, latency, and maintenance hurdles. Representing a paradigm shift in the graph space, PuppyGraph is not a traditional graph database but a graph query engine designed to run directly on top of your existing data infrastructure without costly and complex ETL (Extract, Transform, Load) processes. This "zero-ETL" approach is its core differentiator, allowing you to query relational data in data warehouses, data lakes, and databases as a unified graph model in minutes.  

Instead of migrating data into a separate, specialized graph database, PuppyGraph connects to your existing data sources, including PostgreSQL, Apache Iceberg, Delta Lake, BigQuery, and more, and creates a virtual graph layer on top. This architecture separates computation from storage, enabling petabyte-level scalability and eliminating the data duplication, pipeline fragility, and maintenance headaches associated with traditional graph deployments.

Key Features:

• Zero-ETL Querying: Query your existing data directly—no pipelines, no duplication. PuppyGraph connects to data warehouses, lakes, and databases in place.
  
  
• Fast, Scalable Execution: Its distributed, vectorized engine delivers high performance for complex multi-hop queries, even across petabyte-scale datasets.
  
  
• Gremlin and openCypher Support: Use familiar graph query languages without learning something new. PuppyGraph supports both openCypher and Gremlin out of the box.
  
  
• Schema-as-Config: Graph models are defined through simple JSON schema files. This makes it easy to update, version, or switch graph views without touching the underlying data.
  
  
• Easy to Deploy: Start querying in minutes via Docker or cloud marketplaces—no heavy setup or infrastructure overhead.
  
  
• Data Stays in Place: PuppyGraph doesn’t move or copy your data. It respects your existing storage, access controls, and security policies.

Best For: Teams that want to perform graph analytics on relational data in real time, without ETL or heavy infrastructure, especially when cost, simplicity, and fast setup matter.

Neo4j

Neo4j is the long-standing market leader and is often considered the most mature and developer-friendly graph database available. Unlike JanusGraph's decoupled design, Neo4j is an integrated, native graph database, meaning its storage and processing engines are purpose-built for graph data from the ground up.

Its biggest claim to fame is Cypher, a declarative, pattern-matching query language that is widely praised for its intuitive, ASCII-art-like syntax. For developers coming from a SQL background, Cypher often presents a gentler learning curve than Gremlin's programmatic style. Neo4j has cultivated a rich ecosystem with extensive documentation, a vibrant community, and excellent tooling like the Neo4j Desktop, which provides a seamless local development experience.

Key Features:

• Native graph architecture: Stores data in a graph format for highly efficient traversal performance ("index-free adjacency").
• Cypher query language: An intuitive, declarative language that simplifies writing complex graph queries.
• Mature ecosystem: Offers extensive tooling, libraries, and a large community for support.
• Managed service: Provides Neo4j AuraDB, a popular and robust fully managed cloud service that handles all operational overhead.
• Open core model: The Community Edition is open source (GPLv3), while the Enterprise Edition offers clustering, advanced security, and commercial support.

Best for: Teams that want a mature, easy-to-use graph database with strong tooling, managed cloud options, and a gentle learning curve.

Amazon Neptune

Amazon Neptune is AWS's fully managed, proprietary graph database service. It is purpose-built for the cloud, featuring a unique architecture that separates compute and storage. This allows the custom, distributed storage layer to scale automatically up to 128 TiB, while you can scale compute resources independently by adding up to 15 low-latency read replicas to a cluster.

One of Neptune's most compelling features is Neptune Serverless, which automatically provisions and scales compute capacity based on real-time workload demands. This can lead to significant cost savings for applications with variable or unpredictable traffic patterns. Neptune is also a multi-model database, supporting both the Property Graph and RDF (Resource Description Framework) models. Crucially, it supports multiple query languages, including Apache TinkerPop Gremlin and openCypher, giving teams flexibility and providing a clear migration path from other systems.

Key Features:

• Fully Managed Service: AWS handles all patching, backups, scaling, and infrastructure management, eliminating operational burden.
• Cloud-Native Architecture: Separation of storage and compute provides high availability and independent scaling.
• Serverless Option: Automatically scales compute resources to match workload, optimizing for cost and performance.
• Multi-Language Support: Compatible with Gremlin and openCypher, preventing vendor lock-in on query languages.
• Deep AWS Integration: Seamlessly integrates with services like S3 for bulk loading, IAM for security, and SageMaker for graph machine learning.

Best for: AWS-based teams looking for a fully managed, multi-model graph database that integrates seamlessly with their cloud environment.

TigerGraph

If your primary concern is raw analytical performance, TigerGraph is a name you need to know. TigerGraph is a native parallel graph database built from the ground up on a Massive Parallel Processing (MPP) architecture. This design automatically partitions graph data across all nodes in a cluster and executes queries in a distributed, parallel fashion.

This architecture makes TigerGraph exceptionally fast for deep-link analytics, queries that involve traversing many hops across very large datasets. Its primary query language, GSQL, is a powerful, Turing-complete, SQL-like language. GSQL queries are compiled directly into C++ code for execution, squeezing out maximum performance. Across numerous benchmarks, TigerGraph has demonstrated significant speed advantages over competitors for complex OLAP workloads.

Key Features:

• Native Parallel (MPP) Architecture: Designed for extreme performance on large-scale analytical queries.
• GSQL Query Language: A Turing-complete, SQL-like language that compiles to C++ for high-speed execution.
• Real-Time Data Loading: Capable of loading massive amounts of data in real-time while simultaneously serving queries.
• In-Database Analytics: Allows for the creation of complex algorithms and machine learning features directly within the database.
• Managed Cloud Service: Offers TigerGraph Savanna for a fully managed experience.

Best for: Enterprise teams running complex, high-throughput graph analytics where performance and deep traversals are critical.

NebulaGraph

Nebula Graph is a high-performance, open-source, distributed graph database engineered for managing and analyzing large-scale graph data in real-time. Written in C++, it is designed to handle graphs with hundreds of billions of vertices and trillions of edges with millisecond latency. Its architecture is built on a shared-nothing, storage-and-computing-separation model, which allows for independent scaling of its query and storage layers, ensuring high availability and horizontal scalability.  

The system is composed of three distinct services: a Meta Service for managing schema and cluster state, a stateless Query Service for processing requests, and a distributed Storage Service (using RocksDB by default) for persisting data. Nebula Graph uses its own SQL-like query language, nGQL, which is compatible with openCypher, making it accessible to developers familiar with traditional database languages.  

Key Features:

• Distributed Architecture: Separates compute and storage, enabling independent horizontal scaling and high availability.  
• High Performance: Optimized for low-latency queries (milliseconds) and high throughput, capable of handling massive datasets efficiently. Performance benchmarks show it excels with large-scale data.  
• Scalability: Designed to manage graphs with trillions of edges and vertices, making it suitable for web-scale applications.  
• SQL-like Query Language: Its native query language, nGQL, is easy to learn and compatible with openCypher, lowering the barrier to entry for developers.  
• Open Source and Flexible Deployment: The core is licensed under Apache 2.0, with options for an Enterprise edition and a fully managed cloud service. It can be deployed on-premises, in the cloud, or via Docker and Kubernetes.  

Best for: Teams that need a scalable, Cypher-like graph database with strong OLTP performance and built-in tooling, without managing separate backends.

Conclusion

JanusGraph remains a powerful choice for organizations that need flexibility and control over a scalable, distributed graph system. But that flexibility often comes with complexity—especially when stitching together multiple backends and maintaining a multi-system deployment.

Today, teams have more choices. Whether you prioritize ease of use, performance, scalability, or zero-ETL access to existing data, there's an alternative that fits.

• PuppyGraph offers a clean break from traditional graph databases, letting you define and query graph models directly on existing relational data without ingesting or duplicating anything.
  
  
• Neo4j shines for teams that want a polished developer experience and a mature ecosystem.
  
  
• Amazon Neptune appeals to cloud-first teams who value managed infrastructure and integration with AWS.
  
  
• TigerGraph delivers unmatched performance for deep, multi-hop analytics.
  
  
• Nebula Graph provides scalable, low-latency graph operations for web-scale workloads in an open-source form.
  
  

Choosing the right tool depends on your architecture, your use case, and your team's needs. But if your goal is fast, flexible graph analytics without rethinking your entire data infrastructure, PuppyGraph offers a compelling path forward. Try the forever-free PuppyGraph Developer Edition or book a demo with our team and see how quickly you can start querying your existing data as a graph.