Free download on the Mac App Store with in-app purchases.
First released
2026
Last verified
Answer
Spillway is a SwiftUI macOS app that treats each load test as a document you edit, save, and share instead of a script or YAML file. Plans are composed visually from HTTP requests, loops, conditions, think times, CSV data, and regex or JSON extractors feeding token expressions, and can be driven with either a virtual-user.
About
Spillway is a SwiftUI macOS app that treats each load test as a document you edit, save, and share instead of a script or YAML file. Plans are composed visually from HTTP requests, loops, conditions, think times, CSV data, and regex or JSON extractors feeding token expressions, and can be driven with either a virtual-user or a target throughput model with ramp, spike, and soak shapes. Runs stream live throughput, error-rate, and p50/p90/p95/p99 charts alongside per-sample request and response inspection, and two executions can be compared to spot regressions. OAuth 2.0, custom headers, cookie jars, and client certificates are built in; distributed runs across multiple machines are announced as coming soon.
Best for
API and protocol throughput or latency campaigns
Teams that want a free tier before committing to paid capacity
Groups comfortable scripting in None
Not the best fit when
Teams unwilling to operate generators, results storage, and scaling
Architecture and concurrency
Spillway is commonly operated as self-hosted software with scenario authoring in None. Concurrency and distribution depend on how you size workers or injectors.
Specs
Scripting
None
Protocols
HTTPHTTPSREST
Operating systems
macOS
Tags
macosapiguino-code
CATALOG LAST VERIFIED · 2026-08-12
Frequently asked
ANSWER-SHAPED
Who is Spillway for?
Spillway is best for engineers focused on API and protocol-level throughput and latency. It offers a freemium path, so teams can start small before buying capacity. Vendor: Craig Edwards. Deployment model: self-hosted. Free download on the Mac App Store with in-app purchases.
How does Spillway differ from Artillery?
Compared with Artillery, Spillway is freemium while Artillery is open source; scripting centers on None rather than JavaScript, TypeScript. Spillway lists protocols HTTP, HTTPS, REST; 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 Spillway use?
Spillway uses None for scripting or scenario definition. Runtime model: GUI-oriented authoring with optional scripting for advanced flows. OS support: macOS. Protocols: HTTP, HTTPS, REST. 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 Spillway?
Spillway 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. Pricing model: Free download on the Mac App Store with in-app purchases.
What are known limitations of Spillway?
Spillway 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.