Best API Testing Tools in the UK

Find and compare the best API Testing tools in the UK in 2025

Use the comparison tool below to compare the top API Testing tools in the UK on the market. You can filter results by user reviews, pricing, features, platform, region, support options, integrations, and more.

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    Loader.io Reviews

    Loader.io

    SendGrid

    $99.95 per month
    Loader.io offers a free load testing service that allows users to stress-test their web-apps and apis with thousands concurrent connections. Register your app using the API or web-interface to test it. For the duration, we'll simulate connections to you application. You can monitor the test in real time and share the results with your colleagues.
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    RapidAPI Reviews

    RapidAPI

    RapidAPI

    $59 per user per month
    RapidAPI Testing provides functional API testing and monitoring solutions. It offers an intuitive UX, supports any API type and integrates with RapidAPI Marketplace or Enterprise Hub. RapidAPI Testing allows users and enterprises to: Ensure API Functionality - Create complex functional tests for deep validation APIs. Centralize Monitoring – Monitor and manage API tests across multiple geopolitical boundaries. Increase efficiency - Connect to the CI/CD pipeline and collaborate across teams. Natively integrate with RapidAPI Marketplace or Enterprise Hub. RapidAPI Testing allows you to create functional test flows that can be customized and validate REST, SOAP, or GraphQL APIs. A simple interface allows users to choose from three test generation options, allowing both developers and non-developers the ability to create code-based, visual, or automated test generation.
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    TestMace Reviews

    TestMace

    TestMace

    $4 per month
    Test Mace is a powerful cross-platform tool that allows you to work with an API and create automated API tests. You can create scenarios and requests using variables, authentication and syntax highlighting. Our simple UI interface makes it easy to create complex scenarios. You can perform complete regression testing in just one click. You can assign a request result to an variable and gain access from other nodes. You can save authorization tokens, response headers, and parts of a response. Run your scenarios in different environment contexts. This can be used to organize stage, development, and production environments. If you are using one of the most common types, embedded authentication methods will allow you to perform authentication. To share your request with colleagues, you can use the quick share feature. To copy a specific node's URL, press a button. You can now send the url to your teammate.
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    Ping-API Reviews

    Ping-API

    Ping-API

    $5 per month
    Our generator allows you to create JavaScript or CoffeeScript test scripts. Write a script to set the request parameters, and then validate the response. Ping-API will run the test script on global servers in U.S.A, Japan, Germany, Singapore. Schedule testing to inspect your APIs. We will send you the failure information via email, Slack, and HipChat. Ping-API allows users to create JavaScript and CoffeeScript test scripts to test their APIs. Write script to set request URL parameters, headers, and body. Write script to validate headers and body. Script generator. Programming is not a problem. The generator will generate a test script if you just set the parameter for your API. It's easy! This is the use case for web developers. If my web goes down or the response is not expected, please notify me. Ping-API schedules your tests every minute or hour. We will notify you if the test fails.
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    vREST Reviews

    vREST

    vREST

    $20 per month
    Validate your REST APIs' responses. Write test cases, run them, validate it's response, find out failure reasons with Diff Report, and many other things. You can integrate tools such as JIRA, Jenkins and Team City, Bugzilla, Slack, and more. It can be easily integrated with any build system or continuous integration system. This allows your team to stay in sync even during test failures. Your front-end team will not need any back-end APIs to develop with API Mocks. This allows your front-end team to work alongside the back-end teams. vREST is different from its competitors due to its easy-to-use interface and great customer support team. Do you feel lazy to create test cases? You don't have to be lazy to write test cases? You can execute your test cases by simply running a command from your terminal with vrunner. To validate your APIs every time you deploy an application, all you need to do is Run a Command
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    API Science Reviews

    API Science

    API Science

    $29 per month
    APIs are more than plumbing. They are critical to your business, your apps and your reputation. You need to ensure they are always working and performing as expected. Customers shouldn't be able to call you to complain about your API being down. Slow or unreliable APIs shouldn't cause bad app reviews. APIs were not the core of modern applications when traditional monitoring services were created. API Science is specifically designed for monitoring APIs. Sure, we understand REST, JSON, OAuth, XML. No problem. You can monitor how developers and apps use your APIs with our global monitoring network. You can set up API monitors using your own tests. Your APIs are then called from anywhere in the world. We'll notify you immediately if anything goes wrong. You can quickly identify errors, outages, and performance issues. Troubleshooting is faster and easier.
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    Bright Security Reviews
    Bright Security is a developer-centric Dynamic Application Security Testing solution (DAST). This allows organizations to ship secure APIs and applications quickly and economically. Its method allows for quick and iterative scanning to identify critical security flaws early in the SDLC, without compromising quality or delivery speed. Bright empowers AppSec teams with governance to secure APIs and web applications while allowing developers to take control of security testing and remediation. Bright's DAST solution, unlike legacy DAST solutions that were designed for AppSec professionals, is easy to deploy and finds vulnerabilities late in the development process. It can be deployed in the Unit Testing phase, and run through the entire SDLC, learning from each scan and optimizing. Bright helps organizations detect and fix vulnerabilities early in the SDLC. This reduces risk and costs.
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    APIsec Reviews

    APIsec

    APIsec

    $500 per month
    Hackers are looking for loopholes in API logic. Learn how to protect APIs and prevent data leaks and breaches. APIsec identifies critical flaws within API logic that can be exploited by attackers to gain access to sensitive information. APIsec pressure-tests every API to make sure no vulnerabilities can be exploited. This is in contrast to traditional security solutions which look for common security problems such as cross-site scripting and injection attacks. APIsec will reveal vulnerabilities in your APIs before they are released to the public. This allows you to identify potential exploitable endpoints and prevent hackers from exploiting them. To identify potential vulnerabilities in your APIs, run APIsec tests at every stage of the development process. This will help you to find them before they go into production. Development doesn't need to slow down for security. APIsec runs at the speed DevOps and gives you continuous visibility into your API security. APIsec tests can be completed in minutes, so there's no need to wait for the next scheduled Pen-test.
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    API Discovery and Lifecycle Manager Reviews
    TeejLab is a leader in applying machine learning and data science to assist organizations with the evolving challenges of API economy. The only industry solution for API governance at global enterprises. How secure and compliant are you with legacy apps and mainframes communicating via APIs with internal and external information systems? The world's first software composition analysis tool for discovering hidden, private or public APIs through a curated knowledge database. TeejLab is doing Web APIs what Google did for websites. TeejLab's modular product portfolio is designed to address the diverse API Governance needs of communities and enterprises, while also allowing for flexibility to add new capabilities as they evolve. We have the right product for you, whether you are an engineer looking to benchmark APIs, or a producer or consumer of APIs who is ready to expand your product range.
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    EthicalCheck Reviews

    EthicalCheck

    EthicalCheck

    $99 one-time payment
    You can submit API test requests via UI form. Or invoke EthicalCheck API by using cURL/Postman. Request input requires a public-facing OpenAPI URL, an API authentication token valid at least 10 minutes, an active license key and an email. EthicalCheck engine automatically creates custom security tests for APIs. It covers OWASP API Top 10 List. Automatically removes false negatives from the results. Creates a developer-friendly report and emails it to. According to Gartner APIs are the most common attack vector. API vulnerabilities have been exploited by hackers/bots, resulting in major security breaches across thousands of organizations. False positives are automatically separated from real vulnerabilities. Generate enterprise-grade penetration test reports. It can be shared with customers, partners, developers, and compliance teams. EthicalCheck works in the same way as a private bug bounty program.
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    Backengine Reviews

    Backengine

    Backengine

    $20 per month
    Describe examples of API requests and responses. Define API logic in natural language. Test your API endpoints, and fine-tune prompt, response structure, or request structure. Integrate API endpoints into your applications with just a click. In less than one minute, you can build and deploy sophisticated application logic with no code. No need for individual LLM accounts. Sign up for Backengine and get started building. Our super-fast backend architecture is available immediately. All endpoints have been secured and protected, so that only you and your application can use them. Manage your team members easily so that everyone can work on Backengine endpoints. Add persistent data to your Backengine endpoints. A complete replacement for the backend. Use external APIs to integrate your endpoints.
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    Firecamp Reviews

    Firecamp

    Firecamp

    Free
    Navigate easily through a clutter-free interface that allows you to focus on the important things: efficiently testing and collaborating APIs. Firecamp's user-friendly interface, along with a variety of powerful features streamlines API development workflows and improves collaboration between team members. Set values to variables that can be reused across the entire platform. Publish beautiful API documentation to your team and community. Run API Collection tests in the terminal, or in CI/CD pipeline. Test and debug auth endpoints using a variety of supported auths.
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    One APIMarketplace Reviews

    One APIMarketplace

    DigitalAPICraft

    $99 per month
    One APIMarketplace is a platform-independent enterprise-grade API marketplace that allows you to publish, consume, and collaborate. It will accelerate your API journey and enhance the developer experience. Reduces API complexity and sprawl by operationalizing APIs. This includes making them discoverable and consumable. It also makes them easy to access and collaborate. One APIMarketplace reduces the time to market through the effective adoption of APIs, API usage and performance insights. Empower developers to adopt APIs faster with intuitive documentation, community engagement and resources. One APIMarketplace simplifies the discovery and use of your APIs. This ensures a hassle-free and smooth experience for both developers and businesses. Access detailed documentation and test APIs before integration. Our analytics dashboard provides insights into API usage and performance as well as user behavior.
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    Zoho QEngine Reviews

    Zoho QEngine

    Zoho

    $101.57 per month
    Zoho QEngine features such as no-code, manual coding, and low-code allow you to manage all test cases on multiple platforms from one place. Create, develop and manage automated functional tests in collaboration with your team. The test automation software from Zoho QEngine is all you need to manage your entire testing cycle. Zoho QEngine is equipped to test web apps across browsers. Build and manage automated test case for web applications faster with minimal coding/no code. Zoho QEngine makes automated testing of web applications simple. Zoho QEngine's mobile test cases are up to standard with its Appium compatibility and real devices, mobile emulators, and simulators. Zoho QEngine, a cloud-based software for API testing, allows you to test, assert, manage and automate any type of API request or response. Zoho QEngine's interoperability testing API provides the functionalities that you need in a testing software.
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    Testfully Reviews

    Testfully

    Testfully

    $49 per month
    Testfully has it all, from powerful API client features to advanced monitoring and testing. Enjoy the flexibility of cloud-based and offline-only storage. The seamless team collaboration and easy migration are all available in one multiplatform tool. Transfer your data directly from Postman or Insomnia into Testfully. Set global, folder, and environment variables that are scoped by workspace or user. Create any HTTP request by customizing auth, parameters and headers. Add teams, assign roles and control folder access. Supports major schemes such as OAuth2 to streamline and secure authorization. Testfully allows for quick and effective testing, without the need to code. Advanced API testing is now accessible and hassle-free. With just one click, execute all requests in a directory simultaneously, sequentially or randomly. Validate responses and conduct contract testing using a declarative form. No coding is required.
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    Qyrus Reviews
    Test web, mobile, APIs, and components to ensure seamless digital user experiences. Test your web applications in confidence. Our platform provides you with the assurance you need for speed, efficiency, cost reduction, and more. Use the Qyrus Web Recorder in a platform that already has low code and no-code to build tests faster. Test-building features such as data parameterization and variables global can be used to maximize coverage across scripts. Scheduled runs allow you to run comprehensive test suites while on the move. AI-driven script repairs can be used to combat flakiness, brittleness and element shifts due to UI changes and UI changes. This will ensure that the application is functional throughout the entire development lifecycle. Qyrus Test Data Management (TDM) allows you to manage all your test data in a single place, removing the need for tedious data imports from external sources. Users can generate synthetic data in the Test Data Management System for use during runtime.
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    Speedscale Reviews

    Speedscale

    Speedscale

    $100 per GB
    Validate your app's performance and quality with real-world traffic scenarios. Preview code performance to quickly identify problems and ensure your app is running optimally when the time comes to release. To better prepare for production, mimic real-life scenarios, simulate load, and create intelligent simulators of third-party or internal backend systems. You don't need to create expensive new environments every time you test. Cloud costs are further reduced by the autoscaling feature. You can ship more code faster by avoiding complex frameworks, manual test scripts, and homegrown frameworks. You can be confident that your new code changes will handle high traffic scenarios. Protect the customer experience, prevent major outages and meet SLAs. Simulate internal and third-party backends to ensure more reliable and affordable testing. No need to create expensive, end-toend environments that can take days to deploy. Migrate seamlessly off legacy architecture without affecting the customer experience.
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    Hoverfly Cloud Reviews

    Hoverfly Cloud

    Hoverfly Cloud

    $10 per month
    Hoverfly Cloud, a SaaS API Simulation solution owned by iOCO allows you to speed delivery, reduce costs and get resilient software on the market faster. Hoverfly Cloud, designed from the ground-up for integration, automation and performance, allows developers and testers to replace APIs that their applications rely on with flexible lightweight simulators. This allows developers and test engineers to decouple the development and testing processes from unreliable and expensive test systems, and restrictive API sandboxes. API simulations can be configured in a way that they reproduce unexpected API behaviors, such as high latency and random failures. This allows applications to respond gracefully to API misbehaviors. Hoverfly Cloud has extremely low running costs, even when performing complex and extreme testing. Create API simulations and mocks in just minutes, without the need for expensive, complex features.
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    MockAPI Reviews

    MockAPI

    MockAPI

    $5 per month
    Create endpoints quickly, generate custom data and perform operations using a RESTful Interface. Define the resource schema, and data generators per field. Set up relationships between resources and generate endpoints automatically. MockAPI allows you to easily mock up APIs. It is meant to be used as a prototyping/testing/learning tool.
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    Mocki Reviews

    Mocki

    Mocki

    $15 per month
    Enter a response body to get your API URL. Mocki can be used to create a full-fledged fake API. Mocki allows you to create, run and deploy mock APIs. Use mocks to design APIs, serve static responses and simulate error scenarios. Sign up for a 7-day free trial today. Sync your mock service with your code repository and keep it up-to-date with the latest updates without having to manually update your service. Our managed hosting solution ensures that your mock service will always be available to any consumer. You can access a dashboard that will give you insights into how your mock service has been used. You can run your services using our open source CLI. This allows you to run your service locally without needing an internet connection in order to access external services. A mock API is also useful for testing backend applications. It is common for your API or service to need to call external services via HTTP.
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    Sparrow Reviews

    Sparrow

    Sparrow

    Free
    Sparrow is a complete tool set that helps R&D teams achieve excellence in API development by focusing on design first. Use cURL for API requests and support methods such as GET and POST. It simplifies API interaction, handling headers and data easily. A collaborative open-source solution for API creation, allowing the creation of exceptional APIs to be streamlined. Collaborations allow developers to shift their development practices early in the process. This leads to faster development and higher-quality APIs. Parallel testing is easy across multiple environments, so you can get insights on the move. Sparrow provides powerful tools to secure and manage your API data, along with self hosting capabilities. Users have complete control over their test environment. Sparrow's latest insights, developments, and resources will keep you up to date.
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    Speakeasy Reviews

    Speakeasy

    Speakeasy

    $250 per month
    Speakeasy is an API integration platform that generates type-safe, handwritten SDKs for over nine programming languages including TypeScript Python Go Java and C#. These SDKs can reduce API integration times up to 60%, by eliminating the need to write boilerplate code. They also reduce common implementation errors and increase API accessibility among various programming communities. Terraform simplifies the creation and management of Terraform providers by allowing the definition of resources, operations, and automatic validation from OpenAPI specs. Speakeasy also offers end-toend testing workflows that enforce API standards, protect against breaking changes and provide SDK documentation with up-to date usage snippets. Speakeasy is trusted by top API companies. Its solutions include robust SDKs and Terraform providers as well as comprehensive testing tools.
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    Hoppscotch Reviews

    Hoppscotch

    Hoppscotch LTD.

    $19 per user per month
    Hoppscotch helps you create and test APIs quickly, allowing you to ship your products faster. Create APIs faster, document them and share them automatically. Develop without switching tabs from prototyping to production. Hoppscotch has everything you need to develop APIs easily. Create workspaces for teams. Control access to workspaces. Work with your team in real time. Deploy Hoppscotch to your own servers. Organize requests into collections or folders, and share them within your team. Manage your environment variables, and use them anywhere. View and manage the history of your requests. Modify headers and authenticate requests. Generate random data. Test your APIs, and write assertions to be used in the response. Use Hoppscotch with your native language. We support over 30 languages. Track all activities in your workspace. Who did what when? Login to Hoppscotch using your existing SSO provider. Manage your users, workspaces and more.
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    Leapwork Reviews
    Leapwork is the world's most accessible platform for automation. Leapwork is a visual, no code approach that makes it easy for IT and business users to automate repetitive tasks. This allows enterprises to adopt automation faster and scale it up more quickly. More than 400 global companies use Leapwork across all industries, including banks, insurance companies, life science, government, and aerospace. NASA, PayPal and Daimler are just a few of the clients. The company has offices in Europe, America, and Asia. It is headquartered in Copenhagen.
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    Runscope Reviews
    An API Monitoring (Runscope API test) is a series of HTTP requests executed in a sequential order to evaluate the correctness, uptime, and performance of an API. You can define Assertions for each step of the test to validate response data, and Variables that will extract data for subsequent requests. If all assertions pass, the test is considered passed. If any assertion fails or another error occurs, the test is deemed to be failing. Customers shouldn't be telling you about downtime or breakages. Runscope supports all the notification tools you use, including PagerDuty and HipChat, Slack, HipChat email, webhooks, and more. Monitor service performance to quickly detect and fix API problems. With the API Dashboard, you can stay ahead of intermittent failures so they don't become major problems. Verify that your API calls are structured and contain the information you expect. Flexible assertions that are powerful and easy to use give you complete control.