Linkerd vs Istio

A 2024 service mesh comparison

"Like many organizations, we considered Istio. But our research led to the conclusion that we would need a team of developers just to run it. It was too complicated, requiring ongoing, active attention—it’s not fire and forget. We looked at other solutions and ended up with a shortlist of half a dozen different options, but the one that stood out was Linkerd." Steve Gray, Head of Trading, Entain Australia

The service mesh is here to stay, and Kubernetes users around the world are deciding between Istio and Linkerd. In 2024, engineers are increasingly choosing Linkerd. Why is that?

In this comparison, we’ll walk you through the similarities and differences between the projects and when to choose one over the other.

The big picture

Pioneered the service mesh category in 2016 and coined the term
Purpose-built lightweight micro-proxy written in Rust
Lightest, fastest, and simplest service mesh thanks to its Rust-based micro-proxy
5th CNCF project and first service mesh to achieve graduation status (2021)
Created and maintained by Buoyant
Launched in 2017
General purpose proxy Envoy written in C++
Lots of overhead and complexity due using a powerful proxy like Envoy — a proxy that can do much more than a service mesh needs
Donated to the CNCF in 2022
Created by Google and IBM and now mainly maintained by third-party vendors after Google started divesting from it around 2022

Istio and Linkerd are both service meshes. The two projects have similar goals: to add reliability, security, and observability to Kubernetes applications. Both projects work by adding transparent “sidecar proxies” alongside application instances, and providing features by through these proxies.

Despite these similarities, the two projects couldn’t be more different. Istio is a “big vendor” project, with the complexity to match. Linkerd takes the opposite approach, focusing on simplicity (especially operational simplicity), performance, and user experience.

We’re biased, of course, but here’s our take on the comparison.

Linkerd is faster

Linkerd is significantly faster than Istio, meaning that your users and customers will experience better performance. In the project’s recent service mesh benchmarks, Linkerd added anywhere from 40% to 400% less latency than Istio did. Why? Linkerd’s state-of-the-art, ultralight Rust “micro-proxy” is designed just for the service mesh use case and can be highly optimized to handle this traffic.

Linkerd vs Istio latency

In their 2024 service mesh benchmark, Service Meshes Decoded: a performance comparison of Istio vs. Linkerd vs. Cilium, UK-based cloud consulting firm LiveWyer concluded  that "Linkerd is the fastest and most efficient mesh among all those tested."

Further reading: Linkerd vs Istio benchmarks
"We installed Linkerd and everything was just working right — we didn’t have to add any extra configurations or anything like that. With Istio, we would have had to make a bunch of changes to make everything work." Chris Campbell, Platform Architect, HP

Linkerd is smaller

Linkerd consumed significantly fewer system resources than Istio, especially at the critical data plane level (which scales with your application). In the project’s recent service mesh benchmarks, Linkerd used an order of magnitude less CPU and memory than Istio. The primary reason? Linkerd’s ultralight Rust “micro-proxy”, designed specifically for the service mesh use case.

Linkerd vs Istio memorybulb
Further reading: Under the hood of Linkerd's state-of-the-art Rust proxy

Linkerd is more secure

Linkerd makes it easier to build secure systems. Linkerd’s configuration surface area is significantly smaller than that of Istio, and security features like mutual TLS are on by default. The moment you install Linkerd, all communication between meshed pods is automatically encrypted and authenticated with mutual TLS, no configuration required!

Istio uses the general-purpose Envoy proxy, which is built on C++, a legacy language known for its memory-related security vulnerabilities. By contrast, Linkerd’s data plane is built in Rust, a language that avoids the entire class of memory-related CVEs through advanced memory management. The Linkerd team believes that the future of the cloud will be built in Rust.

"One astonishing fact sticks out: the majority of vulnerabilities fixed and with a CVE assigned are caused by developers inadvertently inserting memory corruption bugs into their C and C++ code." A proactive approach to more secure code — Microsoft
Further reading: Why Linkerd doesn't use Envoy

Linkerd is simpler

Linkerd’s core design philosophy is about minimalism: a service mesh should be simple, light, and secure, and do as little as possible to get the job done. Linkerd is especially focused on reducing operational complexity: the human toil involved in maintaining, operating, and being on-call for a production service mesh.

"We’ve felt encumbered by [Istio’s] complexity every time when configuring, maintaining or troubleshooting in our clusters. After yet another ‘Oh… This problem was caused by Istio!’-moment, we decided the time was ripe to consider the alternatives. We looked to the grand ol’ Internet for alternatives and fixed our gaze on the rising star Linkerd." Frode Sundby, Senior Engineer, NAV

Istio takes a different approach and presents an all-in-one solution. Many features and configurations are supported, from built-in ingress controllers to multiple types of multi-cluster operations. This means that Istio is extremely difficult to operate and configure.

Further reading: Linkerd's design principles

Linkerd is the first graduated CNCF service mesh

Linkerd is the first graduated service mesh in the Cloud Native Computing Foundation, the same foundation that hosts Kubernetes, Prometheus, and other core cloud native projects. Linkerd has publicly committed to open governance, has over 200+ contributors from all over the world, and a public steering committee of end users.

Further reading: Announcing Linkerd's CNCF Graduation

You can get support directly from the Linkerd maintainers

While Istio support requires going to a third-party vendor, you can get Linkerd support from the creators and maintainers themselves. Linkerd help is available around the clock in a variety of levels, from its thriving and friendly open source community all the way to 24x7x365 Linkerd support from the creators of Linkerd.

The bottom line

If security is a primary concern; if you want a service mesh that “just works” and gets out of your way; if speed and resource consumption are critical; and if you are bought into the Kubernetes model of operations—Linkerd will be the best choice.

But don’t take our word for it: give Linkerd a try and see for yourself. You can follow this Linkerd 101 video tutorial for a step-by-step guide and, if you have questions, just hit us up on the Linkerd Slack. We’re always happy to help!