What Is Canary Testing? Canary Development Overview

Canary testing involves releasing your product to a small group of users or servers first. This early release is your “canary”—your chance to test any changes before a full rollout.

The process gets its name from an old mining practice. Miners would bring canary birds into coal mines to detect dangerous gases. Being more sensitive, the birds would succumb to the toxic air before humans, alerting miners to evacuate quickly.

In product development, canary testing serves a similar purpose. Releasing changes to a small subset first lets teams detect issues before they affect all users. The approach enables early problem identification and quick rollbacks if needed, minimizing risk and ensuring smoother releases.

There are a few different ways to implement canary testing:

• User-based: You can target a certain percentage of your user base, say 5%, to receive the canary release first—you “send” the updated product to them. Geographic region, customer tier, or other segmenting factors may determine this canary group.

• Environment-based: Instead of specific user groups, you might first distribute the new version to a canary environment, like a cluster of servers, and direct a percentage of your traffic there (i.e., you don’t know who is in the group). If all is OK, you can gradually direct more users to the canary version and eliminate the control.

• Hybrid: You could also use a hybrid approach. For example, you might create a canary group of users based on certain factors, sending half to the canary environment and the other half to the control. You can then directly compare each.

Whatever your product or methods, you must closely monitor and analyze the canary group’s experience in those first few hours or days. Analytics tools, error tracking, and user feedback channels are crucial during this stage.

If everything looks good to go with your canaries, you can continue unleashing the updates to your entire user base and infrastructure.

However, if issues crop up, you can quickly roll back just that group while investigating what caused the problem.

Using canary testing means trading off some added complexity for reduced launch risk and more sustainable product releases. For many businesses, these benefits generally outweigh the cost of extra learning and added resources.

However, it’s helpful to know the main pros and cons of canary testing before deciding.

Pros

• Reduced launch risk: By rolling out changes incrementally, you limit your exposure to failures or bugs when you launch a product. If something goes wrong, you quickly roll back the affected group rather than risk impacting all of your users.

• Real-world product testing: Pushing canary releases to actual users means you get real-world data and feedback that no amount of staging environment testing can replicate. It’s beneficial for cloud vendors and overcoming the “it works on my machine” phenomenon.

• Continuous update delivery: Canary testing enables frequent releases and software iterations by breaking the release process into safer, smaller batches. This helps you eliminate any big quarterly deployment nightmares.

• Side-by-side metric analysis: With canary testing, you can parallel run the new and old versions to compare accurate performance metrics instead of just hypothesizing. This method supports your data-driven decision-making.

Cons

• User-experience fragmentation: Different user groups on different software versions can create a disjointed user experience. Effective release management and communication are vital to overcome this.

• Implementation complexity: Canary testing requires sophisticated infrastructure, deployment pipelines, and monitoring to carry it out effectively. It’s not just a simple flip of the switch.

• Potential cost increase: The added complexity and overhead of multiple environments, monitoring tools, and higher release cadence can increase your team’s operational costs.

• Difficulty pinpointing issues: With only a few canary users, it may be harder to catch the minor problems that haven’t affected everyone.

Getting started with canary testing is relatively straightforward. You don’t need to go all-in immediately—begin with some lower-risk projects to gain experience before using canary testing on more significant, complex updates.

The exact path you take will depend on the needs of your product and software. These are some of the most crucial steps and considerations.

Set goals and metrics

First, determine what success looks like for your team. What are you trying to achieve with canary testing? Are you aiming for faster release cycles? Fewer disruptions? Improved scalability?

Set your goals, then define the metrics to measure your progress, including tracking error rates, response times, and user engagement.

Choose your strategy

There’s no one-size-fits-all approach to canary testing. You’ll need to pick a strategy that suits your business and your product—think about what makes the most sense for your situation.

Decide if you want a user-based, environment-based, or hybrid canary strategy. Your choice will depend on your product's architecture, infrastructure, skills, resources, and other factors.

Sort out segmentation

If going down the user-based route, you must determine how to split up those canary cohorts. This might be by location, customer type, or another user segmentation.

Make sure you have a clear understanding of your user base and how to segment it effectively. You should also take care to capture enough meaningful cross-sections for reliable testing.

Build automation and monitoring

Try to automate as much of the canary testing process as possible, from deploying updates to collecting and analyzing the data.

Ensure your pipelines and infrastructure can enable these rollouts and rollbacks. Monitoring tools are also crucial for analyzing the canary group behavior and alerting you to real-time issues.

Test

Once you’ve set everything up, it’s time to put your canary launch to the test. Start small and gradually increase the scope as you gain confidence.

For even more peace of mind, you could stabilize new builds through staging and testing environments to spot any issues before your canary rollouts.

When testing has begun, keep a close eye on your metrics and be ready to reverse course if things start to go south.

Keep communicating

Through successes or failures, keep stakeholders informed about how the testing is going. Let them know what you’re testing, why, and if any problems arise.

Canary insights are great learning opportunities for product, engineering, and operations teams. Transparency builds trust and ensures everyone is on the same page.

Iterate and improve

Finally, don’t forget to learn from each canary test and use that knowledge to improve your product and strategy.

What worked well? What could be better? Analyze your completed rollouts, get feedback from users and different internal teams, and iterate. The more you run canaries, the smoother your process will become, and the more you’ll get out of the testing.

Implementing canary tests is one thing, but doing them well is another. Building a process takes commitment, but the payoff is worth it—you minimize launch risks while accelerating product innovation.

Here are some tips and best practices to keep in mind.

Define clear rollback criteria

Before any canary test, set specific criteria for when to roll your product back to a stable version.

What are the signs that things are going wrong? Thresholds like error rates, performance degradations, or other metrics reaching certain levels should sound the retreat alarm.

Outlining these limits upfront lets you know when to revert to a previous version to reduce disruption.

Start small and ramp up

Begin your canary testing with a small percentage of users (1% to 5%) or a limited number of features. Starting small lets you catch any issues early on and lessen the impact on a broader user base.

If everything goes well and you’re confident the changes are working smoothly, you can slowly increase the canary group size or scope. It’s much better to underestimate than overestimate at first.

Mix up your canary groups

Avoid consistently using the same canary group for testing. If that cohort has unique characteristics, this can lead to skewed or biased results.

Instead, mix it up and test canaries on different segments of your user base. This will help you identify a wider range of issues and ensure thoroughly tested updates.

Embrace feature flags and toggles

Feature flags and toggles are considerable assets to canary testing. They enable you to dynamically turn features on or off, giving you greater control over your testing process.

Embrace feature flags to test new features in isolation and toggle them on only when you’re confident they’re ready.

Don’t skip proper staging

Proper staging is essential before rolling out updates to your canary groups. Use staging environments to test your changes in a controlled setting before sharing them with actual users.

Use pre-production environments (including staging, development, and quality assurance) to catch bugs before you send your updated product into the real world.

Monitor continuously

Monitoring is the lifeblood of canary testing. Look at your product’s performance, error rates, and usage patterns during the canary analysis, and encourage and collect user feedback.

Combine these stats with insights from additional analytics platforms for an even deeper look at what’s happening and the actions you should take. This is particularly vital for addressing any immediate, more critical problems.

Collaborate across teams

Canary testing is a team effort that requires collaboration and communication across different departments.

Actively involve others, including your engineers, QA testers, customer support, and leadership in the rollout process. Keep them in the loop, letting them know of any noteworthy changes by scheduling regular updates.

This collaboration ensures everyone is aligned, reduces the risk of miscommunication, and helps address issues more effectively. Each team can also provide valuable perspectives to help you analyze the outcomes of your test. 

Many businesses integrate feature flagging into their canary strategy. Feature flags work by showing your canary group certain features or capabilities of your product—this means you don’t need to deploy an entirely new version.

They act as control toggles. You target individual user cohorts and turn different features on or off for them using flags. You can then monitor how these features perform in a controlled way before a broader rollout.

Say you want to test a new shopping cart checkout flow or a redesigned dashboard. Instead of pushing a whole new release, you can toggle that isolated functionality to “on” just for your canary users.

Using feature flags adds more confidence and control than typical canary testing. If the new feature performs poorly or has problems, you can turn off the contained experience via the flag without impacting anything else.

Delivering new products or versions is challenging enough without having to worry about botched releases disrupting your users or business.

Canary testing helps prevent those headaches, and Amplitude ensures the canary process is simple, secure, and data-led from end to end.

It provides your team with tailored-made feature flagging, monitoring, and analysis capabilities to help you carry out canary tests confidently.

With a few clicks, you can:

• Create secure feature flags to toggle different experiences on or off
• Precisely target different user segments or environments for rollouts
• Monitor critical metrics and track KPIs in real time during canary testing periods
• Analyze granular user behavior to understand how people are experiencing and interacting with your canary versions

You can also use the A/B testing platform to run more controlled feature experiments within your canary groups—essentially a “canary of canaries” approach, enabling you to release changes with maximum confidence and reliability.

Is canary testing the same as A/B testing?

Although canary testing and A/B testing share some similarities, the two are slightly different. An A/B test involves testing multiple versions or experiences simultaneously to measure their impact and find the most effective one—such as testing two versions of a landing page copy against each other.

Canary testing focuses on rolling out a single new version to a few users before a wider launch. It’s a more controlled release with fewer risks than head-to-head multivariate testing.

However, you can combine the two techniques. For example, you may run A/B tests among your initial canary cohorts first to determine which changes to canary launch.

What's the difference between a smoke test and a canary test?

A smoke test is a primary, initial testing method that checks for critical functionality—it essentially tests if your software runs in the first place. You usually need to pass a smoke test to move to further testing, like canary tests.

Smoke tests typically occur internally—the canary test then extends your analysis to the real world.

What's the difference between a blue-green test and a canary test?

Blue-green deployments involve two identical production environments (“blue” and “green”) where you can easily switch between the old and new versions. It gives you a practice run of a release, while canary testing exposes your product changes to real users.

The two methods can complement each other in a release strategy. For final validation, you may use a blue-green test before implementing canary testing for some of your actual users.