PropEr review
A focused Erlang tool for generated properties, stateful models, and smaller failure cases.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
PropEr is an open-source property-based testing tool for developers writing Erlang programs. Rather than checking only hand-picked examples, teams define properties and input types, then generate inputs to check whether those properties hold. Its strongest fit is Erlang teams testing stateful systems: it can model state-machine behavior and exercise it with generated sequences of symbolic API calls. It can also test functions from Erlang specifications, making it relevant to teams that want property checks within an Erlang codebase rather than a separate testing platform.
The feature set goes beyond basic random input generation. PropEr can use its own types and Erlang native types to generate values, and it can derive generators from abstract data type API functions. For stateful testing, teams provide an abstract state-machine model and PropEr generates command sequences to compare behavior against that model. When a property fails, the tool attempts to shrink the failing test to a smaller counterexample, which can make the problematic case easier to inspect. Targeted property-based testing is also included. EUnit and Common Test integrations support using PropEr within those Erlang test workflows.
PropEr is open-source software with a free plan and self-hosted deployment; the published product details describe no paid tier. Support is community-based, so teams should be comfortable working with that support model. Its scope is deliberately tied to Erlang, which makes it a poor fit for organizations seeking one property-testing product across different programming languages. Erlang teams that need generated input, state-machine testing, and failure shrinking should consider it; teams looking for hosted deployment, commercial support, or a broader-language tool should look elsewhere.
PropEr pros and cons
- Where it wins
- Generates inputs from PropEr types and native Erlang types
- Tests stateful systems with generated command sequences
- Attempts to shrink failures and supports targeted testing
- Where it doesn't
- Supports Erlang rather than a range of programming languages
- Requires a self-hosted deployment
- Support is community-based
PropEr fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update