Knapsack Pro

Semaphore CI vs Heroku CI comparison of Continuous Integration servers
What are the differences between Semaphore CI and Heroku CI?

Semaphore CI

https://semaphoreci.com

Heroku CI

https://www.heroku.com/continuous-integration
Unique feature

Autoscaling made easy / Great CLI

Heroku Flow

Type of product

SaaS

SaaS

Offers a free plan

Yes

1,300 service minutes every month. Plans to release a free tier for open source projects.

No (partial)

For CI only, the cost starts at $10 for pipeline, plus a variable amount depending on how long the build runs for (prorated per second). The servers used for CI cost $250 for a full month, which means you get about 3 hours for $1. For hosting, there's a free tier, limited to 1 web/1 worker with 512 MB RAM. One of the more annoying limitations is that free dynos are put into sleep mode after 30 min. of inactivity, which increases loading times considerably.
Predictable pricing

Yes

Semaphore doesn't have traditional pricing tiers, instead it lists the types of machines you can use and their pricing per second of service. They plan to release an annual plan at some point.

Yes

Clearly defined, offers a calculator.
Support / SLA

N/A

Not clear if they offer any real SLA on support.

Yes

Paralellism
Every CI servers tends to address this differently (parallel, distributed, build matrix). Some of it is just marketing, and some is just nuance. For this table, parallel means that tasks can be run concurrently on the same machine, distributed means that tasks can be scaled horizontally, on multiple machines
How to split tests in parallel in the optimal way with Knapsack Pro

Yes

Allows defining a custom build matrix such that your build can be parallelized accross several different environments.

Yes

Up to 16 nodes. You can ask Heroku support to enable up to 32 parallel dynos.
Distributed builds
distributed means that tasks can be scaled horizontally, on multiple machines
How to split tests in parallel in the optimal way with Knapsack Pro

N/A

N/A

Containers support / Build environment

Yes

Allows running builds inside docker containers

Yes

Builds run in isolation on new dynos (Heroku containers). Wide support via buildpacks: https://devcenter.heroku.com/articles/buildpacks
Analytics / Status overview
Analytics and overview referrs to the ability to, at a glance, see what's breaking (be it a certain task, or the build for a specific project)

Yes

Yes

Great visual overview built-in.
Management support
How easy is it to manage users / projects / assign roles and permissions and so on

Yes

Yes

One of the more mature solutions for teams on the market, Heroku Teams is available for free for 1-5 people, and comes at a cost for 6+ team members: https://www.heroku.com/pricing#team-comparison. Allows setting roles and app-level permissions with ease.
Self-hosted option

No

No

Hosted plans / SaaS

Yes

Yes

Build pipelines
A continuous delivery pipeline is a description of the process that the software goes through from a new code commit, through testing and other statical analysis steps all the way to the end-users of the product.

Yes

Allows defining complex build workflows with ease

Yes

Very easy and intuitive process that allows defining a pipeline from code commit, to code review (review apps), user acceptance testing and production deployment, via Heroku Flow. Works best if the project is also hosted on Heroku.
Reports
Reports are about the abilty to see specific reports (like code coverage or custom ones), but not necesarily tied in into a larger dashboard.

N/A

Yes

Ecosystem
Besides the official documentation and software, is there a large community using this product? Are there any community-driven tools / plugins that you can use?

N/A

Yes

Wide array of 3rd party add-ons available via Heroku Elements: https://elements.heroku.com/addons. Custom buildpacks are also available for almost any stack you might be using (over 5500 buildpacks available at the moment)
Specific language support: Ruby
Some CI servers have built-in support for parsing RSpec or Istanbul output for example and we mention those. Some others make it even easier by detecting Gemfiles or package.json and automate parts of the process for the developer.

Yes

Provides rich documentation on integrating Semaphore CI in Ruby projects. Also provides sudo access if you need to install system dependencies or C extensions.

Yes

Although not specifically built in to Heroku, it's guaranteed that any Ruby specific need that might arise would be solved via add-ons, buildpacks or other integrations available.
Specific language support: JavaScript

Yes

Provides rich documentation on integrating Semaphore CI in Javascript projects

Yes

Although not specifically built in to Heroku, it's guaranteed that any Javascript specific need that might arise would be solved via add-ons, buildpacks or other integrations available.
Integrations
1st party support for common tools (like Slack notifications, various VCS platforms, etc)

Yes

Integration with GitHub and Slack. They allow building iOS projects via their macOS Mojave VM image.

Yes

The strongest built-in integrations are with GitHub and Slack (ChatOps) but even allows integrating 3rd party CI servers in the workflow if you so require, among others.
API
Custom integreation is available, via an API or otherwise, it's mentioned separately as it allows further customization than any of the Ecosystem/Integration options

No

Yes

Offers a feature rich API that allows CRUD operations on the most important features, such as promoting an app to production, or inspecting a specific pipeline.
Auditing

Yes

Yes

Additional notes

List of features is based on Semaphore 2.0

Running Rails tests in parallel on Semaphore CI 2.0 with dynamic test files split

How to leverage Heroku CI to run your tests faster?

Introduction to Knapsack Pro Heroku add-on

Semaphore CI parallelism integration

Heroku CI parallelism integration

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