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

Deploy your sites to global Netlify infrastructure

Every commit gets its own deployed version. Automatically attach a new Deploy Preview at a unique permanent URL whenever you submit a Pull/Merge Request. Set Netlify Build to deploy every branch in the repository for unlimited staging environments.

Heroku Flow

SaaS

SaaS

Yes

300 build minutes/month, 1 concurrent CI build

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.

Yes

Extra 500 build minutes costs $7/month. User seat $15/user/month.

Yes

Clearly defined, offers a calculator.

Yes

99.99% uptime SLA for Starter and Pro plan. Business plan has negotiable SLA.

Yes

Yes

Starter plan (free) has only 1 concurrent build but Pro plan has 3 concurrent builds included.

Yes

Up to 16 nodes. You can ask Heroku support to enable up to 32 parallel dynos.

Yes

High-Performance Builds - The premium build environment gives more concurrency, processing power and asynchronous deploys.

N/A

Yes

When you trigger a build on Netlify, their buildbot starts a Docker container to build your website. The buildbot will look for instructions about required languages and software needed to run your command before running build command. The instructions are called dependencies, and how you declare them depends on the programming languages and tools used in build. Build image selection is available. Until recently, all Netlify sites were built using the same build image. Netlify is experimenting with allowing customers to select from multiple Docker images with different operating systems and software versions.

Yes

Builds run in isolation on new dynos (Heroku containers). Wide support via buildpacks: https://devcenter.heroku.com/articles/buildpacks

Yes

Simple dashboard to see CI builds. Other than CI analytics Netlify has Netlify Analytics that brings data captured directly from their servers for your website.

Yes

Great visual overview built-in.

Yes

Team members managment. Role-based access control only in business plan.

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.

No

No

Yes

Yes

Yes, partially

Simple steps, define your own steps in bash commands

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.

No

Yes

No

There are only small helpful things like incoming webhooks so other services can trigger Netlify deploys, and send outgoing webhooks as a deploy starts, succeeds, or fails.

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)

Yes

It has support for Ruby.

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.

Yes

It has support for JavaScript.

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.

Yes

Netlify has incoming webhooks so other services can trigger Netlify deploys, and send outgoing webhooks as a deploy starts, succeeds, or fails. For instance you can integrate it with Slack.

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.

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.

N/A

Yes