ISG comparison of the public cloud market: who are the leading providers?

In this article, you will read

• which cloud providers lead the European market,
• how T Cloud Public performs in comparison
• and where to download the results free of charge. 

In 2025, T Cloud Public once again confirmed its position as one of Europe’s leading cloud providers. In the key benchmark for the German market, the ISG Provider Lens® Multi Public Cloud, it ranks third, behind Amazon Web Services and Microsoft Azure, and ahead of Google Cloud.  

At the end of 2025, the analyst firm ISG published its cloud provider benchmark once again: the ISG Provider Lens Multi Public Cloud 2025. The report summarizes key developments in the cloud market during 2025 and offers cloud users a comprehensive, up-to-date snapshot of market trends—particularly with respect to providers, their strengths, and their weaknesses.

T Cloud Public has been listed as a Leader in the benchmark since 2018 and remains the only European provider to achieve this distinction. Much has changed since then. While only 13 providers were evaluated in 2018, the Lens assesses 22 cloud providers in 2025. The message to readers of the report is clear: the cloud market continues to evolve, and sustained success requires providers to demonstrate their capabilities anew each year.

Compared with the previous year (2024), T Cloud Public has further strengthened its position. It is now ranked ahead of Google Cloud, and its lead over IONOS has widened.

Through advances in artificial intelligence, the introduction of a marketplace, proven management tools, including the Enterprise/Financial Dashboard, and the upgrade of its CPU base to the latest chip generation, T Cloud Public once again demonstrates a high level of maturity and an ability to evolve in line with market requirements. This progress has also been explicitly recognized by the analysts. 

The analysts identify three key strengths: T Cloud Public stands out for its robust services, top-tier security, and flexibility. Its portfolio offers a broad range of solutions with integrated AI and ML suites. The platform is further strengthened by deep industry expertise and comprehensive services for AI strategy consulting.  

At the same time, the analysts see significant potential in consolidating the Group-wide cloud offerings under the T Cloud umbrella. As noted in the report: “Deutsche Telekom/T-Systems offers a broad private/public cloud portfolio that can deliver high-quality solutions for companies of all sizes and across all industries.”  

The BSI C5 certification is also highlighted as a key assurance of cloud security. In addition, the analysts point to the ongoing certification process, including listing on the BSI website, which is expected to result in IT-Grundschutz certification in the first half of the year.

In addition to its success in the German market, the specially designed Swiss variant also achieved market leader status in the Swiss benchmark. As a result, T Cloud Public has firmly established itself as a business cloud provider in Switzerland as well.  

Beyond the country-specific reports, ISG also examined the European market for sovereign cloud solutions. Here, too, T Cloud Public achieved a Leader position. The analysts note that Deutsche Telekom differentiates itself from competitors through an end-to-end sovereign cloud portfolio under the T Cloud umbrella, with T Cloud Public explicitly recognized as a core component.  

Interested in the detailed results? Download all benchmarks free of charge here! 

You can find a comprehensive overview of the benchmark results and awards received by T Cloud Public here, including the Forrester Wave for European public cloud infrastructures, the iX comparative report on European clouds, and the Cloud Computing Insider IT Award.