VegaLoad vs k6
Checked on 13 October 2026, against k6 v2.3.0.
k6 is a mature, popular load testing tool from Grafana. It is a Go binary with an embedded JavaScript engine. It has a large community, a browser module, and a hosted service.
Choose k6 when you need browser tests, a large extension ecosystem, or Grafana Cloud. Choose VegaLoad when you want many protocols in one binary without building extensions, a first run with no script, and a guarded local agent loop.
At a glance
| VegaLoad | k6 | |
|---|---|---|
| Language and runtime | Go. One static binary. Python scenarios need a local python3 | Go binary with an embedded JavaScript engine |
| How a test is written | One command in direct mode, or a scenario file in JavaScript, TypeScript or Python | A JavaScript script. TypeScript runs with k6 run script.ts. Types are removed, not checked |
| Protocols | 14 built in: HTTP/1.1, HTTP/2, gRPC, WebSocket, MQTT, Kafka, PostgreSQL, MySQL, Redis, RabbitMQ, FTP, SFTP, TCP, UDP | HTTP/1.1, HTTP/2, WebSockets and gRPC built in, plus a browser module. SQL, Kafka, ZeroMQ and Redis come from community extensions. Extensions need a custom k6 binary built with xk6 |
| Pass or fail limits | -threshold, checks and -baseline. A breach exits 3 | Thresholds. A breach commonly exits 99 |
| Reports | Self-contained HTML, JSON and JUnit XML | End-of-test summary. A built-in web dashboard can export a self-contained HTML report |
| Distributed load | Not built in. A Helm chart runs one test as a Kubernetes Job. Distributed load through Harness Resilience Testing is planned | The k6 Operator runs a test across Kubernetes pods. Grafana Cloud k6 is a hosted service |
| AI agents and MCP | MCP server in the same binary with 9 tools. vegaload init sets up Cursor and Claude Code. Host allow-list and audit log | Official MCP server, in preview (k6 x mcp). It writes, validates and runs scripts. It works with Claude Code, Cursor and others |
| License | Apache 2.0 | AGPL-3.0 |
| Import and recording | OpenAPI (vegaload new -from-openapi) and HAR (vegaload import har). JMeter and k6 import are planned | har-to-k6 converts a HAR file. k6 Studio is a desktop app that generates scripts |
The same test in both tools
Ten users, thirty seconds, fail if the 95th percentile is above 500 ms.
VegaLoad
vegaload run -target https://staging.example.com/health -protocol http1 \
-vus 10 -duration 30s -threshold 'p95 < 500ms' \
-allow-target staging.example.com
k6
import http from 'k6/http';
export const options = {
vus: 10,
duration: '30s',
thresholds: { http_req_duration: ['p(95)<500'] },
};
export default function () {
http.get('https://staging.example.com/health');
}
k6 run script.js
We ran the same shape of test for three seconds against a local server. VegaLoad passed. k6 v2.3.0 passed, and it exited 99 when we set the limit to an impossible value.
Choose k6 when
- You need to test in a real browser. k6 has a browser module. VegaLoad does not drive a browser.
- You want a large ecosystem of extensions and community examples.
- You already use Grafana, and you want Grafana Cloud k6 for hosted runs and results.
- You want to run distributed tests on Kubernetes with the k6 Operator today.
Choose VegaLoad when
- You test more than HTTP, gRPC and WebSocket, and you do not want to build a custom binary. VegaLoad has databases, queues, FTP and SFTP built in.
- You want a first run with no script file.
- You want your AI agent to run tests locally, with a host allow-list and an audit log by default.
- You prefer the Apache 2.0 license.
- You plan to scale through Harness Resilience Testing.
About the AI agents
Both tools have an MCP server, so this is not a reason to pick one. The difference is the shape. k6's server runs as k6 x mcp, is in preview, and helps write, validate and run k6 scripts. VegaLoad's is part of the binary. It also runs the protocol-direct commands, and it asks before testing a new host.
About the license
k6 is licensed under AGPL-3.0. VegaLoad is Apache 2.0. If your company has rules about copyleft licenses, read the license text, and ask your legal team. We do not give legal advice.
Moving from k6
See Moving to VegaLoad.