1
Aqueduct, Inc.
United States
ApiOverflow uses cutting edge generative AI technology to learn how to use APIs and convert your questions into usable code.
- Revenue
- $8.5M
- Customers
- -
- Year founded
- -
- Funding
- -
- Team size
- -
- Growth
- -
Top 88 API Design Tools SaaS Companies in May 2026
As of May 2026, there are 88 SaaS companies in API Design Tools. They have combined revenues of $655.2M and employ 5.3K people. They have raised $873.5M and serve 738.8K customers combined.
API Design Tools are software solutions that assist developers in creating, modifying, and managing application programming interfaces (APIs). These tools streamline the process of designing APIs by providing functionalities such as visual interface design, documentation generation, testing, and validation. Primary use cases include developing RESTful and SOAP APIs, as well as ensuring that APIs are user-friendly, secure, and well-documented to facilitate integration with other software applications. Common features of API Design Tools include template-based design, version control, simulation of API requests and responses, and analytics for monitoring API performance. Buyer personas typically include software developers, API product managers, and technical architects who seek to organize development workflows more efficiently and ensure that APIs cater effectively to the needs of both the developers and the end-users. By utilizing these tools, organizations can enhance collaboration among teams and improve the overall quality of their API offerings.
Filters
Sorting: Highest -> Lowest
Top API Design Tools Companies
Showing 10 of 8 companies ranked by annual revenue.
- Revenue
- $8M
- Customers
- -
- Year founded
- 2020
- Funding
- -
- Team size
- 30
- Growth
- 77.78%
3
Ozone API
London, England, United Kingdom
Ozone API is the leading standards based platform that handles the complexity of open banking, making it easy for any financial institution to meet both regulatory and commercial requirements for an open API. Banks using the Ozone API can accelerate their implementation of open APIs, and bring new commercial services to market ahead of the competition.
- Revenue
- $7.2M
- Customers
- -
- Year founded
- 2017
- Funding
- -
- Team size
- 65
- Growth
- -
4
Datafiniti
Austin, Texas, United States
There are billions of web sites on the Internet. Those web sites contain trillions of points of information. All of that information is potential data. Data on businesses, products, homes, people, and much more. All of that data can be used for a wide variety of business applications like lead generation, pricing intelligence, competitive analysis, and much more. The problem is that web data is very hard to access for businesses. Businesses must go through a complicated and expensive process of acquiring, cleaning, bundling, and distributing web data before they can consume it. Datafiniti simplifies all of these steps into a single step of accessing our API. Datafiniti's promise is to take the entire Internet, and using our proprietary technology, transform it into a single database that all businesses can use to access the web data they need. In other words, Datafiniti is instant access to web data.
- Revenue
- $5.6M
- Customers
- -
- Year founded
- 2011
- Funding
- -
- Team size
- 8
- Growth
- -
5
Marvin AI
Oakland, California, United States
Marvin is a lightweight toolkit that enables developers to build reliable, scalable, and trustworthy natural language interfaces. It provides AI functions and bots to easily integrate AI capabilities into existing codebases without requiring extensive AI knowledge.
- Revenue
- $5.4M
- Customers
- -
- Year founded
- -
- Funding
- -
- Team size
- 49
- Growth
- -
6
Buf
Toronto, Ontario, Canada
The Protobuf developer platform Accelerate API development with Buf, the only end-to-end developer platform for Protocol Buffers, gRPC, and Kafka.
- Revenue
- $5.4M
- Customers
- -
- Year founded
- -
- Funding
- -
- Team size
- 49
- Growth
- -
7
Stainless
New York, New York, United States
Stainless is a company that specializes in generating software development kits for APIs.
- Revenue
- $5.1M
- Customers
- -
- Year founded
- 2022
- Funding
- -
- Team size
- 64
- Growth
- -
8
Gram by Speakeasy
San Francisco, California, United States
Speakeasy is a platform that provides developers with the tools they need to craft exceptional API experiences. You can use Speakeasy to generate SDKs, build MCP servers, create Terraform providers and automate documentation.
- Revenue
- $5.1M
- Customers
- -
- Year founded
- 2022
- Funding
- -
- Team size
- 46
- Growth
- -
Inclusion Criteria
- The product must facilitate the design and documentation of APIs. - It should support multiple API protocols and formats (e.g., REST, SOAP). - The tool must include testing capabilities to ensure API functionality and performance. - It should provide features for collaborative design among development teams. - The product must offer a visual interface for defining API endpoints and data models. - Not just a code generation tool; must also facilitate design and testing workflows.