We compare five CI/CD tools that help teams detect flaky tests, investigate failures, and manage follow-up. Semaphore is our top pick for impact-led triage within CI. This comparison is based on documentation and published pricing, not hands-on testing.

Key Takeaways

  • Semaphore is our top pick for CI-native triage, combining automatic identification, disruption analysis, history, labels, and resolution tracking.
  • Buildkite fits teams that want configurable quarantine and ownership workflows, with test results from other CI systems.
  • CircleCI offers same-commit flaky-test detection for organizations with a supported authentication setup.
  • TeamCity uses several detection heuristics and pairs flagged tests with assignable investigations.
  • Bitrise suits mobile teams that want retry-based flake detection and scoped quarantine.

How We Picked These CI/CD Tools

We reviewed vendor documentation and live pricing pages accessed October 22, 2026. Our criteria covered detection signals, delivery impact, history, ownership or ticket follow-up, management controls, and billing units. We did not run test suites or measure accuracy, failure reductions, or debugging time.

Prices use different units: compute minutes, active users, committers, credits, and builds. Compare expected usage and feature access before treating headline amounts as equivalent.

1. Semaphore

Semaphore Pros

  • Automatic flaky-test identification once test reports are configured
  • Prioritization by how much each test disrupts the workflow
  • Historical trends and labels for investigating and grouping recurring failures
  • Ticket linking with the test's Markdown details
  • Resolution-status tracking for managing follow-up

Semaphore Cons

  • Test reports need configuration, and flaky tests may take a few pipeline runs to appear
  • Labels are capped at three per test

Why We Picked Semaphore

We put Semaphore first for teams that want workflow-impact analysis, test history, and resolution tracking together in their CI workflow. Its Flaky Tests Dashboard connects automatic identification with disruption analysis, giving teams a practical basis for deciding which flaky tests deserve attention first. We particularly like that history and labels support investigation beyond the latest failed run.

For follow-up, each flaky test can be linked to a ticket in the team's tracker, with its Markdown details attached. This keeps the investigation tied to the test record. Marking a test resolved changes its Dashboard visibility; engineers still need to repair the underlying cause.

Semaphore Pricing

Semaphore publishes metered CI compute pricing, separate support and success services, and $15 in monthly platform credits. We see value in keeping detection and follow-up within the CI workflow.

2. Buildkite

Buildkite Pros

  • Test Engine flags tests that return different results on the same commit SHA by default
  • Configurable workflows with additional detection options and auto-quarantine
  • Team ownership for follow-up
  • Test insights from other CI tools, including GitHub Actions, Jenkins, and CircleCI
  • Test splitting for parallel jobs

Buildkite Cons

  • Automated workflows are plan-gated: none on Free and one on Pro
  • History windows limit evaluation depth: 24 hours on Free and seven days on Pro

Why We Picked Buildkite

We picked Buildkite for teams that want configurable detection and quarantine workflows through its Test Engine. Team ownership connects flagged tests with the people responsible for follow-up. Quarantine contains disruption but leaves the underlying repair to engineers.

By default, Test Engine treats a test as flaky when it runs more than once on the same commit and produces different results. Workflows add further detection configurations and automated responses on top of that baseline.

Buildkite Pricing

Free covers up to five users and 250k monthly test executions, with no workflows and 24 hours of history. Pro costs $30 per active user per month with 1M executions, one workflow, and seven days of history, then $15 per million additional executions. Enterprise is custom-priced and extends history to 28 days.

3. CircleCI

CircleCI Pros

  • Flags tests that failed and passed on the same commit within a 14-day window
  • Test Insights summarizes the most recent 100 runs
  • Views of the lowest-success-rate and slowest tests, with flaky tests labeled throughout the app

CircleCI Cons

  • Test Insights is supported only for OAuth-authenticated organizations, not those with a circleci/<UID> slug
  • Free flaky-test detection is limited to five tests

Why We Picked CircleCI

We picked CircleCI as a practical first check for teams already using a supported organization setup. Its same-commit detection signal is straightforward to explain, and the run summary provides context for investigation. Failed-test and slow-test views help teams decide which tests deserve follow-up.

The sources reviewed here did not establish automated quarantine or assignment within Test Insights. Teams that need those controls should plan for a separate process.

CircleCI Pricing

Free includes 30,000 monthly credits and five active users, with flaky-test detection capped at five tests. Paid plans start with Performance at $15 per month, and Scale is custom-priced. Total cost still depends on CI usage, and the Test Insights authentication requirement remains relevant when checking access.

4. TeamCity

TeamCity Pros

  • A dedicated Flaky Tests tab per project, showing failure counts, flip rate, and why each test was flagged
  • Several detection heuristics: high flip rate, status changes without code changes, and different results across invocations in one build
  • Assignable investigations for flaky tests
  • Muting for known-flaky tests while repairs continue
  • A free Professional edition for on-premises use

TeamCity Cons

  • The free Professional edition is limited to three build agents and 100 build configurations
  • TeamCity Cloud bills per committer, so cost grows with active contributors

Why We Picked TeamCity

We picked TeamCity for teams that want flaky-test detection built into a mature CI server, either self-hosted or in the cloud. Its heuristics go beyond a single same-commit check, flagging tests with high flip rates and tests whose status changes in builds without code changes. This matters because automated testing only speeds up delivery when teams can trust the results.

Investigations can be assigned to teammates, and for flaky tests the resolution is set to manual. That stops an investigation from closing on its own when the test happens to pass, which keeps follow-up honest.

TeamCity Pricing

The Professional edition is free and includes three build agents and 100 build configurations; each additional agent license adds 10 configurations. Enterprise is a paid server license that also includes three agents. TeamCity Cloud is billed per committer, meaning any user with 10 or more commits in 30 days, with build credits included per committer slot.

5. Bitrise

Bitrise Pros

  • Insights flags tests with inconsistent results on the same code state, including repeated runs within one build
  • Automatic retries in supported testing steps, with tests that pass on retry marked flaky
  • Flaky rate and flaky runs per test case for prioritization
  • Quarantine scoped by workflow, pipeline, or branch
  • A flaky-test environment variable for build automation

Bitrise Cons

  • Test quarantine is limited to Enterprise plans
  • Built around mobile pipelines rather than general-purpose CI

Why We Picked Bitrise

We picked Bitrise for iOS and Android teams that want flake detection inside a mobile-focused CI platform. Its Insights test cases table shows which tests flake most often and which have the most flaky runs, which helps teams decide where to start.

Quarantined tests are skipped in future builds and tracked in a separate Test Quarantine tab until they are removed. Like other quarantine tools, this keeps builds moving but leaves the actual fix to engineers.

Bitrise Pricing

Bitrise offers a free Hobby plan for individual developers. Pro and Enterprise pricing is largely based on the number of monthly builds, and Enterprise is quoted on request. Insights is listed among the platform's add-ons, so confirm what your plan includes.

Conclusion

Semaphore is our top pick for CI-native, impact-led triage. Its documented combination of detection, disruption analysis, history, labels, issue linking, and resolution tracking supports organized follow-up.

Buildkite is our runner-up for configurable quarantine and ownership workflows. CircleCI suits teams with a supported organization setup, TeamCity fits teams that want a self-hosted option with investigations, and Bitrise serves mobile pipelines. Before committing, pilot a representative suite, check feature access, and estimate costs using the vendor's actual billing unit.

FAQ

What is the best CI/CD tool for flaky test detection?

We recommend Semaphore for teams that want detection, impact analysis, history, and resolution tracking inside their CI workflow. For quarantine workflows, self-hosted setups, or mobile pipelines, compare the relevant alternatives above.

Can these tools automatically fix flaky tests?

No. Detection flags inconsistent outcomes, retries repeat execution, and quarantine or muting keeps known-flaky tests from blocking builds. Resolution tracking records status, but engineers still repair the underlying cause.

Are there free options?

Buildkite offers a Free plan without workflows, and CircleCI limits Free flaky-test detection to five tests. TeamCity Professional is free for on-premises use, and Bitrise offers a free Hobby plan.