Semaphore

Semaphore is a CI/CD platform for teams that need to build, test, release, and deploy code across hosted or self-managed runners. It stands out for combining visual pipeline design with YAML output and autoscaling self-hosted agents; artifact allowances and the cost of advanced support deserve close attention.

Overview

A workflow groups one or more pipelines to automate development work, from builds to releases and deployments. Semaphore’s visual builder models those pipelines, generates YAML, and provides visual performance feedback, giving teams a graphical way to shape automation without giving up configuration they can manage as code.

Repositories on GitHub, GitLab, and Bitbucket are supported, as are pull-request checks. Teams can choose hosted runners or self-hosted agents running Linux, macOS, or Windows. The latter can autoscale with Kubernetes or AWS, which is useful when build demand varies or infrastructure needs to stay under a team’s control. Semaphore says it is open source under Apache 2.0 and can be self-hosted.

Key features

Pipeline configuration and capacity

Visual and YAML configuration, plus artifact or dependency caching, make Semaphore adaptable to teams with different workflow preferences. The default allowance of 20 concurrent jobs is substantial for parallel work, while teams that outgrow it can request a higher limit. Self-hosted agents add flexibility, but require teams to manage their own runner environment.

Security and integrations

Semaphore says builds run in isolated sandbox virtual machines that are destroyed after each use, and that data is encrypted in transit with 256-bit encryption and at rest with AES-256. It also reports SOC 2 Type 2 and ISO 27001:2022 certifications, with reports or proof available on request. Slack and webhook notifications, SAML/SCIM, Okta, OpenID Connect, and GitHub SSO appear among its integrations, though some are edition-restricted.

Artifacts and support

Artifact usage is free up to 20 GB of monthly egress and 100 GB of monthly storage; additional use is charged separately. Teams with large artifacts or frequent downloads should include that exposure in their budget. Free support covers account setup, projects, and Git integration, but advanced CI troubleshooting is reserved for paid support plans.

Pricing

Semaphore has a free plan and no free trial. The pricing model is freemium, with usage-based runner charges and paid support tiers. Free usage credits are $15 monthly. Self-hosted execution is priced at $0.00 per month, billed $0.0025/min for any machine.

Hosted runner prices vary by machine. Ubuntu ARM 2vCPU is $0.00 per month, billed $0.003/min; Ubuntu ARM 4vCPU is $0.01 per month, billed $0.006/min; and Ubuntu ARM 8vCPU is $0.01 per month, billed $0.012/min. Ubuntu x64 2vCPU is $0.01 per month, billed $0.0075/min, while Ubuntu x64 4vCPU is $0.02 per month, billed $0.015/min. The macOS 4vCPU option is $0.09 per month, billed only for what you use. These listed monthly amounts are not a substitute for estimating actual usage at the per-minute rates.

Basic Support costs $50.00 per month for email support during business hours, without guaranteed response times. Priority Response Support costs $250.00 per month for email and Slack with best-effort accelerated responses 24/5. SLA Standard Support costs $500.00 per month and adds email, Slack, and a customer portal, with 24/5 coverage and response targets of P1 in 4 hours, P2 in 1 day, P3 in 3 days, and P4 in 1 week. Organizations that need predictable escalation have a clearer commitment at the top tier, while smaller teams can avoid that expense if their support needs are limited to setup and integration help.

The pricing page includes 20 concurrent jobs by default, with higher limits available on request. Free artifact allowances are capped at 20 GB monthly egress and 100 GB monthly storage, and excess usage is charged separately. Those quotas, alongside runner-minute charges, matter more to total cost than the low listed monthly runner amounts alone.

Platforms

Semaphore supports API, Linux, macOS, self-hosted, web, and Windows platforms. Self-hosted agents can run on Linux, macOS, or Windows; hosted runners include Ubuntu and macOS options.

Who it's for

Semaphore suits software teams that want a choice between hosted compute and self-managed runners, especially those that value visual workflow modeling but still want generated YAML. Its GitHub, GitLab, and Bitbucket connections make it a practical fit for teams on those repositories. The company says it serves SMBs, fast-growing startups, and Fortune 500 companies. Teams with substantial artifact traffic should forecast overage costs, and those needing advanced troubleshooting should account for paid support.

Pros and cons

• Flexible execution: Hosted runners and self-hosted agents that autoscale with Kubernetes or AWS suit teams with changing workloads or infrastructure requirements.
• Visual and code-based workflows: The builder generates YAML and provides performance feedback, supporting both graphical pipeline design and configuration-driven work.
• Meaningful default parallelism: Twenty concurrent jobs support parallel builds, with higher limits available by request.
• Artifact overages can add cost: Free use stops at 20 GB monthly egress and 100 GB monthly storage, with additional usage charged separately.
• Advanced support is paid: Free assistance covers setup and Git integration, while CI troubleshooting and stronger response commitments require monthly support fees.

Alternatives

Continuous Integration Software is a broader category to compare if you want to survey CI options beyond Semaphore. For a narrower workflow focus, browse Game Build Automation Software or Mobile CI/CD Software.

GitHub Codespaces is another freemium choice, with Android and iOS as well as desktop and web platforms; its listed 2-core and 4-core compute plans are $0.18 and $0.36 per month respectively. Choose it when those platform options and its compute plans fit better than Semaphore’s CI/CD workflow focus.

Bitrise has a free plan and free trial, and its Hobby plan is free forever for a team of one, with build credits for a small project a few times per month and community support. It may suit a solo user who needs only occasional builds.

Codemagic offers a free plan with one team member, 500 build minutes refilled monthly, one parallel build, and 30 days of build history and artifact storage. It is worth considering when those explicit free-plan limits match a small team’s needs.

GameCI is free and open source, though CI-provider build minutes may cost extra. It is the more focused option to consider when a game-oriented, open-source tool is the priority.

AppVeyor has an open-source plan with unlimited public projects, one concurrent job, five self-hosted jobs, and community support. Consider it if those project and job allowances are a better fit.

Argo Workflows is a free, open-source workflow engine for Kubernetes. It is an alternative to consider for Kubernetes workflow orchestration.

Azure Test Plans has a $52.00 per month Basic + Test Plans plan, billed $52 per user per month, with test planning and tracking. Consider it when test planning and tracking are the main need.

Bitbucket Pipelines offers a free plan for up to five users with unlimited public and private repositories, 1 GB of LFS storage, and 50 build minutes per month. It may suit small teams already using Bitbucket that can work within those free allowances.

Verdict

Choose Semaphore if you want visual pipeline design paired with YAML, multiple major repository integrations, and the option to scale self-hosted runners. Its 20-job default concurrency and broad execution choices are compelling, but artifact overages and paid advanced support are the key reasons to compare alternatives before committing.