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Choose your plan!

API Tokens are valid across networks

Select your plan, power up your options!
Public Tier
We like to give everyone Free access to our API services so everyone is ready to start building.
  • No API Keys required
  • No expiration date
  • 5k requests per day
  • CORs restricted
  • 100 requests/10s
  • 30s Query timeout
Free Tier
Once familiar with our platform, consider our Advanced solution for "production ready" deployment.
  • Requires registration
  • 50k requests per day
  • Not CORs restricted
  • 100 requests/10s
  • 30s Query timeout
Pro Tier
Enhanced resource capabilities that enable you to develop your application with ease.
  • Requires registration
  • 500k requests per day
  • Not CORs restricted
  • 250 requests/10s
  • 60s Query timeout
₳ - (~ $19.99)
per month
Premium Tier
Top-notch resource capabilities, allowing you to relax and not worry about resource consumption.
  • Requires registration
  • 1.2M requests per day
  • Not CORs restricted
  • 500 requests/10s
  • 120s Query timeout
₳ - (~ $49.99)
per month
Custom Tier
A tailor made infrastructure design around your requirements, for optimal resource management, giving you peace of mind.
  • Requires registration
  • Unlimited requests per day


Koios supports four networks for blockchain transactions and development on Cardano: Mainnet, Preprod (testnet similar to mainnet), Preview (test upcoming features) and Guild (short ad-hoc quick testing with long history).
The Mainnet is where real-world, live transactions take place, while the other networks help out for testing and development.

Tiers rate limits

Koios API service offers several tiered options to suit your specific requirements, each with different rate limits. These tiers are designed to provide the ideal combination of access and resources for your application's needs.

Our Public Tier offers a no-cost access to our API services, with no requirement for API keys or subscription expiry. This tier allows for 5,000 requests per day, providing ample space for experimentation and initial projects on our platform.

For more involved deployment needs, consider our Free Tier. Requiring registration, this tier allows a higher daily request limit of 50,000, serving those who are familiar with our platform and ready to upscale their projects.

The Pro Tier is designed for those seeking more extensive resources and a seamless development experience. With a daily rate limit of 500,000 requests, this tier equips you with the necessary resources to smoothly build your application. Note that registration is required, and a monthly subscription fee of ~$19.99 USD applies.

Our Premium Tier is for those who seek top-tier performance and reliability. With a daily request cap of 1.2 million, you can be sure that your application will have the resources it needs. Registration is necessary, and a monthly subscription fee of ~$49.99 USD applies.

In addition to above, there is a payload size limit as indicated in API docsopen in new window.If none of our predefined tiers suit your specific needs, we offer a Custom Tier. This option allows us to tailor-make an infrastructure to perfectly match your needs, providing limitless requests per day for optimal resource management[1].


Each tier comes with a predefined timeout duration for queries, designed to maintain the performance and reliability of our service. Public and Free Tier offer a 30-second query timeout, while Pro and Premium Tiers offer extended query timeouts of 60 and 120 seconds respectively. This ensures that even the most extensive data queries can be processed effectively without overloading the server resources. For Custom Tier, timeouts are negotiable based on your specific requirements and the capability of your dedicated infrastructure.

Query optimization

At Koios, we acknowledge the importance of optimizing queries to ensure efficient and prompt data extraction from the Cardano blockchain. We implement various strategies and techniques to optimize the querying process, delivering timely results[2].

Our dedicated team is continually enhancing the effectiveness of our API services, fine-tuning queries, and implementing cutting-edge algorithms. Optimizing queries minimizes resource consumption while increasing the speed of data retrieval, resulting in a more efficient and responsive API.

We provide comprehensive documentation and guidance to help developers craft efficient queries. Our documentation covers best practices, strategies for query optimization, and advice on structuring queries to maximize speed. Following these guidelines will enable developers to leverage our API services fully and ensure optimal performance for their applications.

We also stay abreast of the latest advancements in the blockchain sector to continually improve our query optimization strategies. As new technologies and procedures emerge, we evaluate their potential benefits and incorporate them into our optimization tactics.


  1. Bear in mind that even unlimited daily requests in custom tiers are subject to the limitations of hardware resources. ↩︎

  2. Note that many of our API endpoints support bulk queries. For instance, /api/v1/address_info can provide details of 50 addresses in a single call. This is only constrained by the query execution time, greatly reducing the number of individual calls required to acquire equivalent data. We believe this feature can significantly enhance your API experience. We do however advise you to kindly use this feature with common sense, to avoid spamming public instances from instance providers. ↩︎