Is Judge0 CE completely free to use?

Yes, Judge0 CE (Community Edition) is open-source and free to download and use. However, you will incur costs for the infrastructure (servers, storage, networking) required to host and run it yourself.

What is the difference between Judge0 CE and the Judge0 API pricing?

Judge0 CE is the self-hosted, open-source software with no direct subscription fees to Judge0. The Judge0 API (or Judge0 Cloud) is a managed service offered by Judge0, which has tiered, usage-based pricing plans starting from a free tier and scaling up for higher request limits and performance.

Does the Judge0 API offer a free tier?

Yes, the managed Judge0 API includes a free tier that allows up to 500 API requests per day, with a maximum execution time of 5 seconds per request and 1 concurrent submission.

What factors determine the cost of self-hosting Judge0 CE?

The cost of self-hosting Judge0 CE is determined by your chosen cloud provider or hardware, including virtual machine specifications (CPU, RAM), storage, data transfer, and any associated managed services like databases or load balancers.

Can I upgrade or downgrade my Judge0 API plan?

Yes, users of the managed Judge0 API can typically upgrade or downgrade their plans as their usage needs change. This flexibility allows for scaling resources up or down based on demand.

Are there any hidden fees with Judge0 API pricing?

Judge0's pricing page for its managed API generally outlines all primary costs associated with each tier, including request limits, execution time, and concurrency. For specific details, it is recommended to review the official Judge0 pricing page directly.

How does Judge0 CE's pricing compare to alternatives like Piston or Glot.io?

Judge0 CE, being open-source, is cost-comparable to other self-hostable open-source alternatives like Piston and RCE.sh, where infrastructure is the main cost. Compared to Glot.io's free API, Judge0's managed API offers paid tiers for higher limits and guaranteed service levels, which Glot.io does not typically provide.

Judge0 CE Pricing: Plans, Tiers, and Real-World Costs (2026)

Pricing overview

Judge0 CE (Community Edition) is an open-source, self-hosted online code execution system. The core software for Judge0 CE is available without direct licensing fees, meaning users can deploy and operate it on their own infrastructure without recurring software subscription costs to Judge0. The primary costs associated with Judge0 CE arise from the underlying cloud resources or hardware required to host and run the service, such as virtual machines, storage, and networking bandwidth (Judge0 CE deployment documentation).

In contrast to the self-hosted Judge0 CE, Judge0 also offers a managed API service (often referred to as Judge0 Cloud or Judge0 API) that operates on a tiered, usage-based pricing model. This managed service provides a ready-to-use API endpoint, abstracting away the infrastructure management for users. Its pricing is determined by factors such as the number of API requests, the maximum execution time per request, and concurrent submission limits (Judge0 API pricing page). This document focuses on the overall pricing landscape, differentiating between the self-hosted CE and the managed API service where relevant.

Plans and tiers

While Judge0 CE itself does not have tiered pricing, as it is a self-hosted solution, the managed Judge0 API service offers several plans. These plans are designed to accommodate different usage volumes and performance requirements. The costs for self-hosting Judge0 CE depend entirely on the user's chosen infrastructure provider and resource allocation.

The managed Judge0 API service typically includes the following tiers:

Plan	Price (Monthly)	Key Limits	Best For
Free	$0	500 API requests/day, 5 seconds max execution time/request, 1 concurrent submission	Testing, small personal projects, evaluation
Basic	$29	5,000 API requests/day, 10 seconds max execution time/request, 5 concurrent submissions	Small-scale applications, educational platforms, early-stage startups
Standard	$99	25,000 API requests/day, 15 seconds max execution time/request, 10 concurrent submissions	Growing online coding platforms, medium-sized assessment systems
Premium	$299	100,000 API requests/day, 20 seconds max execution time/request, 20 concurrent submissions	Large-scale competitive programming, high-traffic coding challenges
Enterprise	Custom	Custom API requests, execution time, and concurrency	Very large organizations, platforms with specific performance or compliance needs

Note: The above table reflects the pricing structure for the managed Judge0 API service as of 2026. Judge0 CE (Community Edition) does not have these direct subscription costs.

Free tier and limits

The managed Judge0 API offers a free tier, which allows users to test the service without incurring costs. This tier is subject to specific usage limits:

Daily API Requests: Up to 500 requests per day.
Maximum Execution Time: Each request can execute code for a maximum of 5 seconds.
Concurrent Submissions: Limited to 1 concurrent code execution.

This free tier is suitable for initial development, testing integrations, or for applications with very low traffic volumes. For self-hosted Judge0 CE, there is no inherent "free tier" in terms of Judge0's own service, as the software is open-source. However, users can leverage free tiers offered by cloud providers (e.g., AWS Free Tier, Google Cloud Free Program) to host Judge0 CE at no cost or reduced cost for initial deployment and low usage scenarios (AWS Free Tier details).

Real-world cost examples

The real-world cost of using Judge0 varies significantly depending on whether the managed Judge0 API is used or if Judge0 CE is self-hosted. Below are cost examples for both scenarios.

Managed Judge0 API Service

Small Educational Platform: An online learning platform hosts interactive coding exercises for 100 students. Each student submits approximately 5 code solutions per day, resulting in 500 submissions daily. The average execution time is 3 seconds. This usage pattern fits within the Basic plan ($29/month), which provides 5,000 requests/day and 10 seconds max execution time.
Competitive Programming Contest: A university hosts a monthly coding contest with 500 participants. During peak contest hours, they might experience 2,000 requests per hour, totaling 20,000 requests over a 10-hour contest period. The average execution time is 8 seconds, and they require up to 10 concurrent submissions. This scenario would likely require the Standard plan ($99/month), offering 25,000 requests/day and 10 concurrent submissions.
Code Assessment for Hiring: A tech company uses Judge0 for automated coding assessments during its hiring process. They process 100 candidates per week, with each candidate submitting an average of 10 solutions. This translates to 1,000 submissions per week, or roughly 140 submissions per day. Given potential peak usage during assessment windows and the need for reliable performance, the Basic plan ($29/month) would likely suffice, providing headroom above their average daily usage.

Self-Hosted Judge0 CE

The cost for self-hosting Judge0 CE is entirely dependent on the chosen infrastructure. Here are some illustrative examples:

Small-Scale Deployment (AWS EC2): Hosting Judge0 CE on a single t3.medium EC2 instance (2 vCPU, 4 GiB RAM) with 50 GB GP2 SSD storage in a region like N. Virginia might cost approximately $30-40 per month. This setup could handle moderate loads, potentially similar to the Judge0 API's Basic or Standard tier in terms of raw processing power, but without the API request limits. This estimate includes the instance, storage, and minimal data transfer (AWS EC2 On-Demand Pricing).
Medium-Scale Deployment (Google Cloud GCE): Deploying Judge0 CE on a e2-standard-4 instance (4 vCPU, 16 GiB RAM) with 100 GB persistent disk on Google Compute Engine could cost around $70-90 per month. This provides more resources for higher concurrency and faster execution, suitable for an actively used competitive programming platform. This cost includes the VM, disk, and basic networking (Google Compute Engine Pricing).
High-Availability Deployment (Kubernetes on Azure): For enterprise-grade reliability and scalability, deploying Judge0 CE on an Azure Kubernetes Service (AKS) cluster might involve multiple nodes, load balancers, and managed databases. A small AKS cluster with 3 Standard_B2s nodes (2 vCPU, 4 GiB RAM each) and associated services could range from $150-$300+ per month, depending on ingress, egress, and storage requirements. This setup provides high concurrency and resilience for critical applications.

These self-hosting costs do not include the operational overhead of managing the infrastructure, applying updates, and ensuring security, which are typically covered by the managed Judge0 API service.

How the pricing compares

When comparing Judge0's pricing (both managed API and self-hosted CE) against alternatives, it's essential to consider the underlying service model and target audience. Key alternatives include Piston, Glot.io, and RCE.sh.

Piston: Piston is another open-source code execution engine that can be self-hosted. Like Judge0 CE, the direct software cost for Piston is zero, with costs primarily driven by infrastructure. Piston also offers a managed API service with tiered pricing. Its pricing structure is generally comparable to Judge0's managed API, often featuring similar request limits and execution time considerations at different price points. The choice between Judge0 CE and Piston for self-hosting often comes down to specific feature sets, language support, and community preference rather than a significant difference in direct software cost.
Glot.io: Glot.io provides a free, open-source API for running code in various languages. It focuses on simplicity and broad language support. Glot.io's primary model is a free-to-use API, making it a direct competitor to Judge0's free tier and potentially more cost-effective for very low-volume applications that do not require dedicated support or higher limits. However, Glot.io does not offer paid tiers for increased limits or guaranteed SLAs, which Judge0's managed API does.
RCE.sh: RCE.sh (Remote Code Execution Shell) is another open-source project for executing code remotely. Similar to Judge0 CE and Piston, the self-hosted version has no direct software cost. RCE.sh may also offer managed services or have community-supported deployments. Its pricing model, if a managed service is available, typically aligns with usage-based metrics like execution time and requests, similar to Judge0's commercial offerings. The differentiation often lies in the specific features, containerization strategy, and ease of deployment.

In summary, for self-hosting, Judge0 CE offers a competitive solution with no direct software cost, placing the financial burden on infrastructure and operational management. For managed API services, Judge0's tiered pricing is competitive within the market, providing scalable options for different user needs, from free testing to enterprise-level deployments. The availability of a robust free tier for the managed API also provides a low-barrier entry point for evaluation and small projects.