CI cost figures are vendor list prices verified April 2026. Actual cost depends on plan, concurrency, and discount terms. Some links are affiliate links. See disclosure.

Last verified April 2026 · 12 min read

The external GitHub Actions runner shootout, 2026 edition

Every vendor has published their own numbers. Nobody has published them side by side with a neutral methodology until now. This is the page that did not exist.

Disclosure: some links below are affiliate links. We may earn a commission if you start a paid plan. This disclosure does not influence the comparison, which uses published rates and benchmark citations from independent sources.

§ 01

Rate and capability comparison

ProviderLinux x86 $/minARM $/minmacOS $/minCold startWarm cacheSetup timeMin/base cost
GH Actions (baseline)$0.008$0.004$0.080~30sactions/cacheBuilt-inNone
Depotaff.$0.004$0.002$0.040~5sBuilt-in10 min$50/mo
Namespaceaff.$0.004$0.002N/A~3sBuilt-in10 minFree tier
BuildJetaff.$0.003$0.002N/A~7sLimited15 minNone
Blacksmithaff.$0.004$0.002N/A~4sBuilt-in10 minFree tier
Ubicloud$0.004$0.002N/A~6sBuilt-in15 minNone
RunsOnaff.Your EC2Your EC2Self-host10-20sYour setup1-2 hrsAWS cost

Mint = best in column. Orange = most expensive. Rates from vendor pricing pages, April 2026. Cold start and cache claims from vendor-published benchmarks.

§ 02

Per-provider analysis

Depot

The most established external runner. Linux x86, ARM, and macOS support. Strong case-study portfolio with published numbers. SOC 2 Type II.

depot.dev

STRENGTHS

  • +Broadest OS support including macOS at $0.04/min (vs $0.08 GH-hosted)
  • +SOC 2 Type II certified, on-prem option available
  • +Built-in Docker layer cache and OCI registry
  • +Best public case-study evidence base
  • +OIDC federation support

WEAKNESSES

  • -$50/month minimum makes it less attractive for small teams under 12,500 min/month
  • -macOS runners not available in all regions

VERDICT

Choose Depot if you need macOS, have a $50+/month CI bill, or need the most mature SOC 2 posture.

Namespace Labs

Namespace focuses on warm-boot runner technology: their runners boot faster than competitors because they keep pre-warmed VMs available. Fastest cold-start at ~3s.

namespace.so

STRENGTHS

  • +Fastest cold-start (~3s vs 30s on GitHub-hosted)
  • +Built-in warm cache technology
  • +Good pricing ($0.004/min Linux, free tier available)
  • +Strong technical content on their blog

WEAKNESSES

  • -No macOS runner support
  • -Smaller case-study library than Depot

VERDICT

Choose Namespace if cold-start latency is a pain point or you want the fastest possible build startup time.

BuildJet

ARM-first runner provider. Offers the cheapest ARM Linux rate at $0.002/min. Strong on ARM-native workloads. Competitive on x86 Linux at $0.003/min.

buildjet.com

STRENGTHS

  • +Cheapest Linux x86 rate ($0.003/min)
  • +ARM-first: $0.002/min ARM, optimised for Graviton workloads
  • +No minimum charge
  • +Good performance benchmarks on Node.js and Python

WEAKNESSES

  • -No macOS support
  • -Limited warm cache compared to Depot/Namespace
  • -Smaller engineering community

VERDICT

Choose BuildJet for the cheapest ARM Linux rate, especially for Node.js, Python, or Go workloads that are already ARM-compatible.

Blacksmith

Newer runner provider with strong AWS-native integration. Built-in warm cache. Competitive rates. Growing case-study base.

blacksmith.sh

STRENGTHS

  • +AWS-native architecture, strong security posture for AWS-first teams
  • +Built-in warm cache
  • +Competitive ARM rate ($0.002/min)
  • +Free tier available

WEAKNESSES

  • -No macOS support
  • -Newer, smaller community and case-study base than Depot
  • -AWS-only (not available in non-AWS deployments)

VERDICT

Choose Blacksmith if you are AWS-native, want strong security without on-prem complexity, and need a free tier to get started.

Ubicloud

Open-source cloud infrastructure with managed CI runner offering. Unique positioning: open-source underpinning means you can audit the full stack.

ubicloud.com

STRENGTHS

  • +Open-source: full stack auditable
  • +Competitive rates ($0.004/min Linux, $0.002/min ARM)
  • +Managed option available
  • +Strong content on CI cost from the Ubicloud engineering blog

WEAKNESSES

  • -Smaller adoption than Depot or Namespace
  • -Managed offering newer than competitors

VERDICT

Choose Ubicloud if open-source infrastructure audibility is a requirement or you want to contribute to the open-source project.

RunsOn

Managed control plane for GitHub Actions on your own AWS. You supply the AWS account; RunsOn handles runner lifecycle, spot management, and GitHub integration.

runs-on.com

STRENGTHS

  • +Your EC2 costs (potentially cheapest total cost at scale)
  • +Self-hosted economics with managed operations
  • +AWS-native: use existing IAM, VPC, security groups
  • +Spot instance support built in

WEAKNESSES

  • -Requires your own AWS account
  • -Cold start is slower than purpose-built providers (10-20s)
  • -More setup than pure managed options

VERDICT

Choose RunsOn if you want self-hosted EC2 economics with managed runner lifecycle, especially if you are already running significant AWS infrastructure.

§ 03

Decision rubric

ifNeed macOS supportDepot
ifNeed cheapest ARM Linux rateBuildJet or Blacksmith ($0.002/min)
ifNeed fastest cold bootNamespace (~3s)
ifNeed AWS-native + SOC 2Blacksmith or RunsOn
ifNeed open-source infrastructureUbicloud
ifNeed self-hosted EC2 economics without full DIYRunsOn
ifWant the most mature community and documentationDepot
ifFree tier, small team, testing the waterNamespace or Blacksmith
ifSpending under $50/month on CI currentlyStay on GitHub-hosted, optimise workflow first
§ 04 · HONEST COUNTERPOINT

When not to switch

!

Your free-tier GH Actions minutes cover your entire bill. Switching adds operational complexity with no financial benefit.

!

You are on GitHub Enterprise with included minutes in your contract. Check the contract before changing your runner configuration.

!

You need SOC 2 compliance and your procurement has already blessed GitHub but not the external runner provider. The friction of vendor evaluation may outweigh the savings.

!

You are under 1,000 minutes per month. The savings are too small to justify any migration effort.

!

Your engineering team has no spare capacity to test and validate the migration. A failed migration costs more than the CI bill in lost developer time.

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FAQ

Is Depot safe to use?+
Depot is SOC 2 Type II certified, uses ephemeral runners isolated per job, supports OIDC federation for secrets management, and offers an on-premises deployment option. Use OIDC instead of long-lived secrets, pin workflow steps to verified action versions, and use Depot's on-prem option if your data classification requires it.
Depot vs BuildJet vs Blacksmith: which is best?+
Need macOS? Depot. Need cheapest ARM Linux? BuildJet or Blacksmith ($0.002/min). Need AWS-native with strong security? Blacksmith or RunsOn. Need fastest cold boot? Namespace. For a general-purpose Linux + ARM workload without macOS, BuildJet is the cheapest at $0.003/min Linux, $0.002/min ARM.
How do I migrate from GitHub-hosted runners to Depot?+
Change runs-on: ubuntu-latest to runs-on: depot-ubuntu-24.04 in your workflow files. That is the complete migration for most workflows. Depot's runner images are compatible with GitHub-hosted runner images. The migration typically takes 30-60 minutes.
What is RunsOn and when does it make sense?+
RunsOn is a managed control plane for running GitHub Actions on your own AWS infrastructure. You provide the AWS account; RunsOn handles the runner lifecycle. It makes sense for teams that want EC2 economics without building their own control plane.
Do external runners support GitHub Actions caching?+
Yes. All major external runners (Depot, Namespace, BuildJet, Blacksmith) support the standard GitHub Actions cache (actions/cache@v4) and are compatible with docker/build-push-action GHA cache. Depot and Namespace additionally offer built-in warm cache that does not count against GitHub's 10 GB cache limit.