Loader.io review
A focused hosted HTTP load-testing service with a useful free tier and clear limits.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Loader.io is a cloud-based performance testing service for web applications and APIs. It targets developers and teams that need to evaluate application capacity and behavior under HTTP load without focusing on browser-based user journeys. Tests can run by client count, request rate, or maintain-load patterns against verified target hosts. Users can configure HTTP methods, headers, parameters, request bodies, payload files, authentication, and response variables through the web interface or API.
The Free plan costs $0 per month and allows 10,000 clients per test, one target host, one-minute tests, and two URLs per test. The Pro plan costs $99.95 per month and expands capacity to 100,000 clients per test, unlimited target hosts, unlimited 10-minute tests, and 10 URLs per test. It also adds advanced analytics and concurrent tests. That makes the free tier suitable for smaller checks, while Pro is better suited to repeated or higher-volume test programs that need longer tests, multiple hosts, or concurrent runs.
Loader.io’s strongest fit is focused HTTP load testing. Its feature set includes DNS verification, real-time monitoring, shareable results, response-time statistics, scheduled tests, completion callbacks, and an API for managing hosts, tests, results, and load generators. It supports distributed load and API testing, but not browser testing, so teams evaluating rendered-page behavior or complete browser workflows should choose another tool. Tests currently run from Amazon’s US-east datacenter, which may matter when test geography is part of the evaluation. Choose Loader.io for hosted HTTP capacity checks and API-driven workflows; look elsewhere for browser performance coverage.
Loader.io pros and cons
- Where it wins
- Free plan supports up to 10,000 clients per test
- Real-time monitoring, shareable results, and advanced analytics
- API, scheduling, callbacks, and configurable HTTP requests
- Where it doesn't
- No browser testing for user-interface performance checks
- Free plan allows only one target host and two URLs per test
- Tests currently run from Amazon’s US-east datacenter
Loader.io fact sheet, pricing and score →
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