Best Free API Monitoring Tools of 2025

Site24x7 provides unified cloud monitoring to support IT operations and DevOps within small and large organizations. The solution monitors real users' experiences on websites and apps from both desktop and mobile devices. DevOps teams can monitor and troubleshoot applications and servers, as well as network infrastructure, including private clouds and public clouds, with in-depth monitoring capabilities. Monitoring the end-user experience is done from more 100 locations around the globe and via various wireless carriers.

Engineered for peak performance and efficient resource use, KrakenD can manage a staggering 70k requests per second on just one instance. Its stateless build ensures hassle-free scalability, sidelining complications like database upkeep or node synchronization. In terms of features, KrakenD is a jack-of-all-trades. It accommodates multiple protocols and API standards, offering granular access control, data shaping, and caching capabilities. A standout feature is its Backend For Frontend pattern, which consolidates various API calls into a single response, simplifying client interactions. On the security front, KrakenD is OWASP-compliant and data-agnostic, streamlining regulatory adherence. Operational ease comes via its declarative setup and robust third-party tool integration. With its open-source community edition and transparent pricing model, KrakenD is the go-to API Gateway for organizations that refuse to compromise on performance or scalability.

Uptrends is all about cloud-based website performance that keeps track of performance, uptime, and functionality of your websites and APIs. The 24/7 monitoring service that proactively test your website and monitor multi-step transactions. Let’s face it—the Internet is a fragile thing. Stuff breaks or slows every now and then. Uptrends lets you know when it does and what exactly happened. Feel free to try Uptrends for 30 days with our free trial!

Sauce Labs is the largest continuous testing cloud in the world for web and mobile apps. This gives development teams from the top digital brands the ability to deliver apps faster, without compromising on quality. With extensive device and testing coverage, streamlined beta distribution, best-in class error monitoring, and constant feedback loops during your app development cycle, you can release better mobile apps faster. Your mobile apps will always work in real-world scenarios on any device and browser. Sauce Labs' end-to-end solutions for mobile quality enable organizations to deliver mobile apps in a modern era of DevOps driven development. They can achieve quality and speed at all stages of app development - from conception to production. We have you covered, no matter what your testing needs are, the application type you're developing, or your role within the mobile SDLC.

Sematext Cloud provides all-in-one observability solutions for modern software-based businesses. It provides key insights into both front-end and back-end performance. Sematext includes infrastructure, synthetic monitoring, transaction tracking, log management, and real user & synthetic monitoring. Sematext provides full-stack visibility for businesses by quickly and easily exposing key performance issues through a single Cloud solution or On-Premise.

Postman serves as a collaborative platform for developing APIs, designed to simplify the entire process of API creation and enhance teamwork, enabling the rapid development of superior APIs. The platform's features facilitate each phase of API construction, making it easier to collaborate and accelerate the creation of high-quality APIs. Users can quickly and effortlessly send requests for REST, SOAP, and GraphQL directly within Postman, optimizing their workflow. Additionally, it allows for the automation of manual tests, seamlessly integrating them into your CI/CD pipeline to safeguard against potential issues when code changes are deployed to production. API behavior can be communicated effectively by simulating endpoints and their respective responses without the need for a backend server setup. You can also generate and publish visually appealing, machine-readable documentation, which helps in making your API more accessible for users. Regular performance and response time checks ensure you stay informed about your API's health, allowing for proactive management. Lastly, Postman fosters a shared environment for API creation and consumption, enabling real-time collaboration among team members.

Better Stack allows you to see inside any stack and debug any issue. Visualize the entire stack. Aggregate all your logs to structured data and query it like a database using SQL. Search, store and centralize your logs in a flash. Do not worry about archiving and rehydration. Dashboards that combine metrics from multiple sources to create a beautiful summary. Monitor everything, from websites to servers. Schedule on-call rotatings, get actionable notifications, and resolve incidents quicker than ever. Be notified by a platform that monitors infrastructures better. Our 30-second check will give you a screenshot and a second by second timeline of the error. We verify each HTTP and ping-based event from at least three locations before we alert. No more false alarms! We have you covered, whether it's monitoring your web page, APIs, pings, POP3, SMTP, IMAP, DNS, or general network monitoring.

We address your most pressing business challenges through adaptable, straightforward, and scalable solutions designed to facilitate your digital transformation journey. Start utilizing our premier business observability platform today to achieve comprehensive visibility across your operations with insights tailored for business needs, powered by AppDynamics and Cisco. Focus on what truly matters for your organization and your workforce, allowing you to monitor, collaborate, and act in real time. By gaining a profound understanding of user interactions and application performance, you can convert efficiency into profitability. Link full-stack performance analytics with essential business indicators such as conversion rates, enabling you to swiftly tackle problems before they have a detrimental effect on revenue. Navigate the uncertainties of the modern technological environment with our easily deployable solutions that promote growth, enhance customer satisfaction, and engage your teams in achieving business excellence. By aligning application performance with customer experiences and key business outcomes, you can ensure that critical issues are prioritized effectively, safeguarding your customers' experiences. The synergy between performance metrics and business success is vital for fostering innovation and maintaining a competitive edge.

SolarWinds®, Loggly®, is a cost-effective, hosted and scalable multi-source log management system that combines powerful search and analytics with extensive alerting, dashboarding and reporting to help you identify potential problems and reduce Mean Time to Fix (MTTR). LOGGLY AT A GLANCE >> Full-stack log aggregation, log monitoring and data analytics Log analytics provides context and patterns for events, as well as anomalies that can be used to gain deeper insights. >> Highly scalable to ingest large data volumes and enable quick searching across large and complicated environments >> Spot usage patterns with application, service, and infrastructure-aligned historical analysis of user, log, and infrastructure data >> Manage by exception: Identify variations from the norm with powerful log formatting capabilities and analytic search capabilities

Testing and monitoring your web services has never been simpler. With Assertible's automated quality assurance tools, you can ensure the reliability of your essential infrastructure by testing and monitoring web services throughout various deployments and environments. Assertible acts as a dependable first line of defense against web service failures, offering straightforward and effective assertions for your APIs and websites. By minimizing false positives in your automated quality assurance tests, you can trust that your APIs remain in good health. While keeping your tests current may seem daunting, Assertible streamlines this process by allowing you to automatically synchronize your API tests with the most recent updates to your specifications. As you modify responses, parameters, headers, and additional elements, updating your Assertible API tests becomes a hassle-free task that requires just a simple click to sync. Furthermore, Assertible seamlessly integrates with your existing tools, enabling functionalities like executing your web application tests upon code pushes to GitHub or sending alerts to Slack in case of any failures, thus facilitating a smoother workflow. By leveraging these features, teams can enhance their development efficiency while maintaining high-quality standards.

SigNoz serves as an open-source alternative to Datadog and New Relic, providing a comprehensive solution for all your observability requirements. This all-in-one platform encompasses APM, logs, metrics, exceptions, alerts, and customizable dashboards, all enhanced by an advanced query builder. With SigNoz, there's no need to juggle multiple tools for monitoring traces, metrics, and logs. It comes equipped with impressive pre-built charts and a robust query builder that allows you to explore your data in depth. By adopting an open-source standard, users can avoid vendor lock-in and enjoy greater flexibility. You can utilize OpenTelemetry's auto-instrumentation libraries, enabling you to begin with minimal to no coding changes. OpenTelemetry stands out as a comprehensive solution for all telemetry requirements, establishing a unified standard for telemetry signals that boosts productivity and ensures consistency among teams. Users can compose queries across all telemetry signals, perform aggregates, and implement filters and formulas to gain deeper insights from their information. SigNoz leverages ClickHouse, a high-performance open-source distributed columnar database, which ensures that data ingestion and aggregation processes are remarkably fast. This makes it an ideal choice for teams looking to enhance their observability practices without compromising on performance.

Testfully offers an extensive array of features, ranging from robust API client capabilities to sophisticated testing and monitoring functionalities. Users can take advantage of versatile cloud and offline storage options, facilitate effortless collaboration among teams, and enjoy straightforward migration, all within a single, comprehensive multi-platform tool. The platform simplifies the transition of data from Postman or Insomnia, allowing for seamless integration into Testfully. With a focus on flexibility and security, users can establish global, environment, and folder variables tailored to either the workspace or individual users. The tool also allows for the customization of authentication methods, parameters, headers, and body content, making it easy to create any HTTP request. Collaboration is made simple as you can invite team members, assign specific roles, and manage folder permissions effectively. Testfully supports major authorization schemes such as OAuth2, ensuring secure and efficient access management. Whether you are dealing with straightforward tasks or more intricate scenarios, Testfully streamlines the testing process without requiring any coding skills, thus making advanced API testing more approachable and user-friendly. Users can execute requests within a folder either simultaneously, sequentially, or in a random order with a single click, enhancing efficiency. Additionally, it allows for response validation and contract testing through a declarative format, further eliminating the need for coding and simplifying the overall testing experience. Overall, Testfully is designed to cater to both novice and experienced users, ensuring that everyone can leverage its capabilities effectively.

Eliminate delays, pinpoint inefficiencies, and troubleshoot problems effectively. Become a part of a swiftly growing network of global businesses that are realizing up to 20 times the value and return on investment by utilizing KloudMate, far exceeding other observability platforms. Effortlessly track essential metrics, relationships, and identify irregularities through alerts and tracking issues. Swiftly find critical 'break-points' in your application development process to address problems proactively. Examine service maps for each component within your application while revealing complex connections and dependencies. Monitor every request and operation to gain comprehensive insights into execution pathways and performance indicators. Regardless of whether you are operating in a multi-cloud, hybrid, or private environment, take advantage of consolidated Infrastructure monitoring features to assess metrics and extract valuable insights. Enhance your debugging accuracy and speed with a holistic view of your system, ensuring that you can detect and remedy issues more quickly. This approach allows your team to maintain high performance and reliability in your applications.

We keep a close eye on your websites, APIs, cron jobs, and other scheduled tasks. Your team receives instant notifications through various channels, including email, SMS, Slack, PagerDuty, and Incident.io. You don’t need to be a tech expert to get started, as our setup is straightforward and user-friendly. Enjoy peace of mind with monitoring that helps you sleep easier at night. Checks can be performed as frequently as every 30 seconds, allowing you to identify problems that could temporarily disrupt your website. Each check can be customized with specific HTTP methods, headers, and bodies according to your needs. OnlineOrNot ensures reliability by conducting each check at least twice before notifying you, with the possibility of additional checks if required. Furthermore, OnlineOrNot monitors your SSL certificates for any impending expirations or potential issues and promptly alerts you if something goes awry. You have the option to perform uptime checks from a single region or multiple locations simultaneously. Since your customers depend on your services, keep them informed with a dynamic status page that updates automatically. You can easily add your customers as subscribers to this status page and send regular updates about any incidents via email to keep everyone in the loop. This proactive approach not only enhances customer trust but also improves overall service reliability.

Cisco ThousandEyes is an innovative platform for network intelligence that equips organizations with profound insights into digital interactions across various environments, including the internet, cloud, and enterprise networks. Utilizing sophisticated monitoring and analytics capabilities, ThousandEyes enables businesses to identify, troubleshoot, and rectify performance challenges that affect essential applications, websites, and services. Its extensive array of tools delivers valuable information regarding network performance, application delivery, and user engagement, allowing organizations to maintain uninterrupted connectivity and enhance user experiences. This platform is widely embraced by Fortune 500 companies and SaaS providers alike, establishing itself as a reliable solution for navigating the intricacies of contemporary hybrid and multi-cloud landscapes. Additionally, ThousandEyes empowers IT teams by equipping them with the tools needed to proactively manage, optimize, and refine their digital infrastructures for improved operational efficiency.

An API Monitoring test using Runscope consists of one or multiple HTTP requests executed in a sequence to assess the availability, speed, and accuracy of an API. During each phase of the test, you can set up Assertions to check the response data and utilize Variables to retrieve information for later requests. A test is considered successful if all assertions are satisfied, whereas it will fail if any assertion does not hold true or if an error occurs, such as issues with the network connection. It’s crucial that your clients are not the ones informing you about service outages or malfunctions. Runscope integrates with your existing notification platforms like PagerDuty, Slack, HipChat, email, webhooks, and others. By actively monitoring your service performance, you can swiftly identify and troubleshoot API issues. Utilize the API Dashboard and daily API Performance Report to stay ahead of sporadic failures before they escalate into significant concerns. Ensure that your API calls' structure and content align with your expectations, as powerful and flexible assertions provide you with comprehensive control over the testing process. With these tools in hand, you can maintain a robust and reliable API experience for your users.

Service Watch is an all-encompassing monitoring solution designed for websites, APIs, web services, cron jobs, and various other online systems. It offers real-time oversight, notifications, and in-depth reports to guarantee that your services operate efficiently. With a variety of alerting methods such as email, SMS, Slack, Discord, and Telegram, Service Watch ensures that you stay informed. We are always innovating and adding new notification channels, so if you have specific needs, please feel free to contact us for assistance.