ITRS named a Visionary in the 2024 Gartner® Magic Quadrant™ for Digital Experience Monitoring

THE STATE OF API RELIABILITY 2025

Real-world insights on API performance in production. Exclusive data from more than 2 billion monitoring checks. The most comprehensive view of API reliability.

Real API monitoring checks

2 BILLION

We analyzed 2 billion anonymized API monitoring checks collected from over 230 global public checkpoints, spanning January to March in both 2024 and 2025, across businesses in 21 different industries.

API UPTIME BY INDUSTRY

API uptime dropped 0.21% YoY, adding ~18 hours downtime annually

Average API uptime dropped from 99.66% to 99.45%, meaning APIs experienced ~34 minutes of weekly downtime in Q1 2024 and ~55 minutes of weekly downtime in Q1 2025. Our industry breakdown compares average API uptime, a fundamental metric of API reliability and business continuity, between Q1 2024 and Q1 2025.

API downtime increased by over 60%

For high-traffic or business-critical APIs especially, downtime impacts company revenue and end user trust. API complexity has grown with industries increasingly relying on microservices and third-party integrations. As a result, modern APIs are distributed and interdependent, meaning more points of failure beyond your control.

KEY TAKEAWAY

When adding external APIs (e.g., LLMs, payment services, or fraud detection), consider third-party API monitoring, failover, or retry logic to minimize risk.

Highest API uptime (2025)

99.93%

Gambling & Gaming’s uptime reflects the industry’s reliance on real-time transactions, in-game purchases, and live betting. Even brief outages can lead to lost revenue, regulatory risk, or a degraded user experience.

Greatest uptime decrease YoY

1.88%

Lifestyle saw the sharpest drop in uptime, likely due to increased reliance on third-party APIs for personalization and scheduling, plus limited infrastructure resilience during peak periods.

Greatest uptime increase YoY

0.98%

Media & Entertainment recorded the largest uptime gain, possibly from broader use of cloud-native platforms and CDN-accelerated APIs, which enable reliable performance across global users and high-traffic streaming events.

API UPTIME BY REGION

North America leads with 99.57% API uptime, but no region is immune to global strain

Looking at API uptime by region helps surface both local infrastructure challenges and broader systemic pressures. Almost all regions experienced a year-over-year decline in API uptime that indicates rising API complexity, traffic volumes, and use of AI are collectively placing strain on digital infrastructure worldwide.

API uptime can differ 0.43% by region (~43 mins of weekly downtime)

The variation in uptime highlights persistent disparities. Regions with mature data center ecosystems and strong connectivity see fewer disruptions, while those reliant on fragmented or less resilient infrastructure are more vulnerable to service interruptions.

KEY TAKEAWAY

To deliver a consistent digital experience globally and mitigate regional service issues, organizations should adopt multi-location monitoring and address infrastructure bottlenecks in areas experiencing disruption.

API PERFORMANCE

High-demand and regulated industries face API performance challenges

Average API response time improved from 695.6ms in Q1 2024 to 560.1ms in Q1 2025, but sectors handling sensitive data or large traffic volumes are at risk of longer response times. As APIs power real-time web services, even small delays can impact the digital experience, transaction success rates, and operational efficiency.

Retail, Manufacturing, and Financial Services show highest latency

Online Retail (946.4ms), Manufacturing (746.2ms), and Financial Services (743.5ms) recorded the slowest response times in Q1 2025. These may result from a mix of data-heavy API calls, legacy system dependencies, and backend complexity, particularly during high-traffic periods or transaction-heavy workflows.

KEY TAKEAWAY

Improving API performance in these sectors requires targeted strategies, such as optimizing request payloads, implementing smart caching, and distributing traffic through regionally-aware delivery infrastructure.

KEY TAKEAWAY

  • Gambling & Gaming achieved the fastest API response time, possibly driven by infrastructure investment to meet performance-sensitive user expectations.
  • Online Retail had the slowest API response time, potentially due to data-heavy, personalized requests, reliance on third-party services, and high processing demands during traffic spikes.
  • Education saw the largest slowdown in API response times year-over-year, which could be caused by increased digital demand, limited infrastructure optimization, and growing reliance on third-party tools for learning management, assessments, and virtual engagement.

Fastest response time

52.4ms

Slowest response time

946.4ms

Greatest increase YoY

307.5ms

“API performance is under pressure in regulated and high-demand industries — even those with relatively low latency have seen significant year-over-year slowdowns, reflecting the impact of growing system complexity and operational risk. Sustained visibility into real-world API performance is critical to improve reliability while maintaining compliance.”

Profile picture of Ryan Terpstra

Ryan Terpstra

Chief Executive Officer, ITRS

SLA TARGETS

Most SLAs set between 99% and 99.9%

The downward trend in average API uptime across all regions signals a growing risk: organizations may soon fall below acceptable thresholds, potentially compromising SLA compliance and customer trust if declines continue.

Most common SLA target

99%

Average API uptime

99.19%

of businesses target 99.99%

1.93%

KEY TAKEAWAY

  • Some industries are setting higher 99.99% targets and demonstrating heightened awareness of API reliability’s business impact; 40% operate in Technology & IT, 25% are in Online Retail, and 20% occupy the Telecommunications sector.
  • As user expectations and digital dependencies grow — driven by the rise of AI and automation, which rely on real-time data and uninterrupted service — we anticipate a shift toward higher SLA targets.

MONITORING ERRORS

APIs account for 67% of monitoring errors

API errors occur when a monitored API returns an unexpected or failed response, such as a 4xx or 5xx status code, indicating issues with availability, authentication, or backend logic. Understanding the cause of monitoring errors, such as API, HTTP, Timeout, or TLS (SSL), helps pinpoint where failures happen and prioritize fixes more effectively.

API errors outpace HTTP, TLS, and Timeout errors in Q1 2025

The prevalence of API errors as the leading cause of monitoring failures suggests growing instability in today’s complex, distributed systems. Inter-service dependencies and configuration drift can lead to failed responses or misrouted traffic. As organizations continue adopting microservices and integrating third-party APIs, it is important to monitor not only availability, but also the functional integrity of API responses.

KEY TAKEAWAY

Proactive health checks can validate authentication flows and payload integrity before issues impact users. Additionally, automated alerts for upstream errors enable rapid triage of deprecated or misconfigured endpoints. These help teams detect and respond to failures faster, particularly in multi-service or third-party-integrated environments where early visibility is essential.

Most common HTTP errors: Authentication and 404 Not Found

The high presence of authentication-related errors highlights frequent challenges in access control, token expiration, and misconfigured permissions. A high volume of 404 Not Found responses points to widespread issues with broken or deprecated endpoints, while the overall error breakdown points to a mix of frontend routing gaps and backend instability.

KEY TAKEAWAY

To reduce HTTP errors, teams should monitor endpoint health using automated checks that validate availability, route accuracy, and authentication success. High volumes of 404 and 500 errors point to the need for coverage of both frontend paths and backend services.

MTTR FOR API ISSUES

Most API incidents have < 5 min MTTR

Understanding Mean Time to Resolution (MTTR) helps organizations benchmark operational responsiveness, identify workflow inefficiencies, and improve service reliability for end users. With API monitoring in place, more than half of API issues can be resolved in under 5 mins.

Prolonged incidents remain a minority, but carry heavy impact

While most industries resolve a majority of API incidents in under 15 minutes, a small proportion of cases still exceed 2 hours. Even when rare, these longer incidents contribute disproportionately to overall downtime. In regulated or user-sensitive environments, such delays degrade the digital experience, risk compliance, and compromise service stability. Improving MTTR for these incidents is essential for resilience at scale.

KEY TAKEAWAY

To improve MTTR, you can adopt a layered monitoring strategy including multi-step checks, concurrent tests, and clear escalation paths. Visibility into how issues unfold across distributed systems enables faster diagnosis and more effective recovery, minimizing both user impact and business disruption.

Quickest industry (2025)

85%

of API issues are resolved in under 5 minutes by businesses in FinTech. This industry consistently addresses issues the fastest, indicating high operational maturity and strong awareness of how API failures can impact both revenue and regulatory compliance.

Slowest industry (2025)

39%

of API issues are resolved in over 2 hours by businesses in Construction. This may reflect limited in-house IT resources, dependence on external vendors, and slower response cycles in sectors not yet optimized for rapid digital operations.

ADOPTION OF ADVANCED MONITORING

35% of businesses now use end-to-end API monitoring

Multi-step API monitors simulate real user journeys by executing a sequence of chained API calls. This enables teams to detect failures that single-step monitors often miss, including issues with authentication, session handling, or interdependent services. As a natural evolution from single-step monitoring, multi-step checks provide immediate, actionable insights, making them a popular entry point for teams advancing their API monitoring capabilities.

Legal Services' use of end-to-end API monitoring highlights the industry’s need for secure, traceable digital workflows. These include document submission, identity verification, and regulatory compliance checks, which require consistent, end-to-end validation.

KEY TAKEAWAY

Implementing end-to-end monitoring improves detection of real-world issues, helping you reduce blind spots, catch failures across more complex API workflows, and strengthen performance for critical services.

API RELIABILITY INDEX

The average API Reliability Index (ARI) across industries is 58%

The API Reliability Index (ARI) is a composite score of how effectively each industry ensures API reliability. The score is weighted 95% toward API uptime, response time, and MTTR, with the remaining 5% based on the adoption of advanced API monitoring capabilities such as multi-step monitors, concurrent tests, and private checkpoints.

The range in ARI spans 54.2%

The disparity in ARI across industries reflects differing levels of operational complexity, regulatory pressure, and digital dependency. Industries that rely on continuous availability such as finance, healthcare, and online services typically invest more in performance optimization. Others may lag due to limited budgets, legacy infrastructure, or slower digital transformation.

KEY TAKEAWAY

To close the ARI gap, organizations must focus on improving three core drivers of API reliability: uptime, response time, and MTTR. This requires optimizing both infrastructure and operational workflows to detect issues quickly, resolve them efficiently, and ensure APIs respond reliably under load. Practices such as multi-step validation, internal visibility, and real-time incident tracking can support these improvements to API reliability, no matter the scale or complexity.

Highest API Reliability Index

86%

Gambling & Gaming leads in ARI due to a combination of high uptime, rapid API response times, and consistently fast MTTR. With user experience and revenue being tightly linked to real-time performance and transaction reliability, this industry likely invests heavily in resilience and rapid issue resolution.

Lowest API Reliability Index

32%

Financial Services' ARI reflects its lower API availability, slower response times, and longer resolution times. These stem from the industry’s structural complexity, strict compliance requirements, and reliance on third-party APIs, all of which increase the risk of service degradation and highlight the need for greater visibility.

“APIs power real-time data access and exchange — capabilities that AI and large language models (LLMs) rely on to deliver timely, context-aware outputs. As adoption of these tools accelerates across sectors, APIs will face increasing pressure to perform. The API Reliability Index reveals disparities in industry readiness, exposing gaps in uptime, performance, and incident response. Closing these gaps is critical to ensure APIs can meet the demand for reliability.”

Profile picture of Ryan Terpstra

Ryan Terpstra

Chief Executive Officer, ITRS

FINAL TAKEAWAYS

Advancing API reliability is essential

Between Q1 2024 and Q1 2025, API uptime fell and systems faced greater pressure under user expectations. To keep pace with reliability demands, organizations must move beyond basic API checks, ensure monitoring reflects real-world usage patterns, and deepen visibility to prevent outages. The businesses leading in API reliability are actively reducing blind spots, accelerating incident response, and delivering resilient digital experiences.

Real API monitoring checks

2 BILLION

Metrics in this report are based on real-time, synthetic API checks captured from our global network of public checkpoints. Uptime, response time, and MTTR were calculated using standardized thresholds across comparable timeframes in Q1 2024 and Q1 2025. Industry-level insights reflect aggregated patterns across 21 sectors, while ARI incorporates both performance indicators and the use of advanced monitoring techniques.

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