TOOL SIGNAL / ACTIVE

Molotov

Tarek Ziadé

Protocol/API Load Open Source Self-hosted

NOT YET REVIEWED · CATALOG DATA

Official site ↗ Source repo ↗
Pricing model
Free; open-source license (see repository).
First released
2017
Latest release
2.7
Last verified
Answer

Molotov is a simple, open-source load testing tool designed for writing load tests in Python using asyncio and aiohttp.

What it is

Molotov is a simple, open-source load testing tool designed for writing load tests in Python using asyncio and aiohttp.

Features

  • Support for scenario-based load testing using Python coroutines
  • Autosizing feature to ramp up workers based on failure rates
  • Support for gRPC load testing
  • Integration with aiohttp for HTTP/HTTPS load testing
  • Flexible configuration for duration, runs, and worker processes
  • Fixtures support for setup and teardown of tests and session configurations

Best for

  • API and protocol throughput or latency campaigns
  • Teams that prefer open-source licensing and self-hosting options
  • Groups comfortable scripting in Python

Not the best fit when

  • Teams unwilling to operate generators, results storage, and scaling

Architecture and concurrency

Molotov is commonly operated as self-hosted software with scenario authoring in Python. Concurrency and distribution depend on how you size workers or injectors.

Fact sheet

Specs

Scripting
Python
Protocols
HTTPHTTPS
Operating systems
macOSLinux
Tags
pythonasyncioaiohttpcli
Repo health
★ 480 · last push 2024-03-18

Latest release

2.7 · Not explicitly specified in repository or documentation

Version 2.7 introduced support for gRPC load testing.

Pricing

Open source, distributed under the Apache License 2.0.

Sources

SHOW SOURCES

LAST VERIFIED · 2026-08-15 · GROUNDED VIA EXA · CURATED BY NAVEENKUMAR NAMACHIVAYAM

Frequently asked

ANSWER-SHAPED
Who is Molotov for?

Molotov is best for engineers focused on API and protocol-level throughput and latency. It is open source, so teams can self-host and extend it. Vendor: Tarek Ziadé. Deployment model: self-hosted. Free; open-source license (see repository). Confirm details against the official site and a short proof-of-concept in your environment.

How does Molotov differ from Artillery?

Compared with Artillery, scripting centers on Python rather than JavaScript, TypeScript. Molotov lists protocols HTTP, HTTPS; Artillery lists HTTP, HTTPS, WebSocket, Socket.IO, MQTT. Status is active versus active. Use the Test Rig to compare full specs side by side before a proof-of-concept.

What scripting language and concurrency model does Molotov use?

Molotov uses Python for scripting or scenario definition. Runtime model: code-first scenarios where virtual users execute scripted behavior under load. OS support: macOS, Linux. Protocols: HTTP, HTTPS. Match these to how your team already authors tests and which systems you must drive under load.

What is the cloud or enterprise path for Molotov?

Molotov is primarily self-hosted; teams typically run generators on their own machines, CI runners, or private cloud. Plan for generator capacity, network access to targets, and result storage yourself. As open source, commercial support or hosted siblings may exist separately. Check the official site. Pricing note: Free; open-source license (see repository).

What are known limitations of Molotov?

Molotov limitations to weigh: self-hosted tools require you to provision, scale, and observe load generators yourself. Status: active. Always validate against your target protocols and scale with a proof-of-concept. Confirm details against the official site and a short proof-of-concept in your environment.