Blacksmith vs Bitrise
Blacksmith is a drop-in for GitHub Actions: you change one runner label and each job runs on a fresh, faster machine. Bitrise is a full mobile CI/CD platform with its own workflows, code signing and releases on Apple silicon Macs and Linux, and it also rents remote dev environments.
The companies and products
Blacksmith
Blacksmith is a CI service: it runs your GitHub Actions jobs on its own faster, cheaper runners instead of GitHub's.
You change the runner label in your workflow file, and each job runs in a fresh Firecracker microVM that boots in under 3 seconds and is destroyed when the job ends. It adds Docker layer caching and sticky disks that carry chosen folders from one run to the next, plus a Testbox CLI in early beta that lets a local coding agent run commands inside a CI job. It is built for teams that want quicker, cheaper GitHub Actions, not as a general sandbox you drive by API; a separate Sandboxes product is marked coming soon.
Bitrise
Bitrise is a mobile CI/CD platform that builds, tests and ships iOS and Android apps on its own Mac and Linux machines.
Bitrise is a different kind of product: a CI service. Each build runs in its own virtual machine from a Bitrise stack, and the machine is rolled back after the build. Since 2026 it also sells Remote Dev Environments, macOS and Linux sessions with a persistent disk where you can start Claude Code from a CLI or drive the machine through an MCP server. It is built for mobile teams.
- Funding
- $95M+ in total
Which use cases each one fits
For each use case, Battleships prices every sandbox provider on the same workload and sorts them from the cheapest monthly bill up. “78th cheapest of 377” means 77 of the other 376 providers run that workload, with every feature it needs, for less. “With limits” means the provider runs it but misses something, so it is listed after every full match. Open a use case for its whole ranking and what each provider misses.
| Use case and its workload | Blacksmith: price rank | Bitrise: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Bitrise can host this in dev environments with 1 to 5 VMs per tier, Blacksmith only runs the CI part, and boat adds hosting on 50 ports and forks. | 248th of 367, with limits $3,607 a month | 38th of 367, with limits $3,403 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An assistant that lives on its machine all month does not fit a CI job on either; Bitrise dev sessions come closest, and boat has no session cap on paid plans. | 78th of 366, with limits $5,463 a month | 73rd of 366, with limits $1,970 a month | 5th cheapest of 366 $657 a month |
| Code interpreter bursts 100 at once · 1 vCPU / 2 GB · 200,000 sessions of 1 min a month | 281st of 345, with limits $488 a month | 289th of 345, with limits $658 a month | 186th of 345, with limits $2,000 a month |
| Sandboxes for your users 300 at once · 2 vCPU / 4 GB · 30,000 sessions of 23 min a month Starting a sandbox per user from your own backend does not fit either CI service, since Blacksmith starts machines from GitHub workflows and Bitrise caps machines per plan; boat does it by API. | 268th of 361, with limits $1,563 a month | 269th of 361, with limits $1,604 a month | Cheapest of 361 $209 a month |
| RL rollouts 1,000 at once · 2 vCPU / 4 GB · 1,000,000 sessions of 3 min a month | 276th of 360, with limits $7,488 a month | 271st of 360, with limits $6,818 a month | 34th of 360, with limits $2,000 a month |
| Agent evals 250 at once · 4 vCPU / 8 GB · 15,000 sessions of 20 min a month | 354th of 364, with limits $1,188 a month | 289th of 364, with limits $1,274 a month | 10th cheapest of 364 $200 a month |
| CI runners 40 at once · 8 vCPU / 16 GB · 6,000 sessions of 12 min a month Blacksmith fits CI cleanly if your jobs live in GitHub Actions, Bitrise is built for iOS and Android pipelines, and boat fits Linux jobs you start by API. | 78th cheapest of 377 $708 a month | 181st of 377, with limits $859 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Bitrise dev environments keep a persistent disk, while a Blacksmith machine is destroyed after each job and keeps only sticky disk folders; boat keeps the whole disk with snapshots every minute. | 180th of 368, with limits $207 a month | 168th of 368, with limits $119 a month | 18th cheapest of 368 $26 a month |
| Computer-use agents 50 at once · 4 vCPU / 8 GB · 20,000 sessions of 15 min a month Bitrise lets an agent see and control a macOS desktop through its MCP server, Blacksmith runners are headless, and boat streams a 60fps Linux desktop. | 243rd of 369, with limits $1,088 a month | 68th of 369, with limits $1,186 a month | 6th cheapest of 369 $200 a month |
| Browser-use agents 50 at once · 2 vCPU / 4 GB · 30,000 sessions of 10 min a month | 131st of 367, with limits $588 a month | 132nd of 367, with limits $746 a month | 7th cheapest of 367 $200 a month |
| Scraping & bots (startup scale) 50 at once · 1 vCPU / 2 GB · 100,000 sessions of 3 min a month | 130th of 346, with limits $719 a month | 131st of 346, with limits $862 a month | 6th cheapest of 346 $90 a month |
| Mass scraping & bots (undetectable) 1,000 at once · 1 vCPU / 2 GB · 3,000,000 sessions of 2 min a month | 262nd of 338, with limits $14,613 a month | 256th of 338, with limits $13,088 a month | 71st of 338, with limits $1,800 a month |
| Parallel red teaming 200 at once · 2 vCPU / 4 GB · 5,000 sessions of 30 min a month | 64th of 360, with limits $350 a month | 73rd of 360, with limits $537 a month | 2nd cheapest of 360 $200 a month |
| GPU eval jobs 10 at once · 8 vCPU / 32 GB · 500 sessions of 30 min a month | Can't run it | Can't run it | Can't run it |
| macOS agents 5 at once · 4 vCPU / 8 GB · 1,000 sessions of 20 min a month Both rent Apple silicon Macs; Bitrise adds iOS simulators and a desktop an agent can drive, and boat has no macOS. | 28th of 36, with limits $1,508 a month | 21st of 36, with limits $400 a month | Can't run it |
Key features
| Feature | Blacksmith | Bitrise | boat |
|---|---|---|---|
| What it is | Drop-in GitHub Actions runners; each machine lives for one workflow job | Mobile CI/CD service, plus Remote Dev Environments for developers and agents | A full Linux VM per agent that you create, stop, start and fork by API |
| Isolation | Firecracker microVM per job, destroyed with its state when the job ends | Each build or session is its own VM; CI VMs are rolled back after each build | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Operating systems | Ubuntu on x64 and ARM, Windows Server 2025 (beta), macOS on Apple Silicon | macOS on Apple silicon with iOS simulators, Linux with Android emulators | Linux (x64) only |
| How you start a machine | A GitHub Actions job; you change the runner label in your workflow | A Bitrise workflow for CI, or the bitrise-cli for a dev session | One API call, SDK or CLI, from anywhere |
| How long a machine runs | Until the job ends, then the microVM is destroyed | CI builds time out at 210 minutes (up to 4 hours on Enterprise); dev sessions stop after 5 idle days by default | Until you stop it; no session cap on paid plans |
| What survives a stop | Only sticky disk folders, up to 5 per job, evicted after 7 days unused | Dev sessions keep one persistent disk, not backed up; CI machines keep nothing | The whole disk, saved every minute and on stop; a stopped sandbox costs nothing |
| Fork | No; every machine starts fresh from a job | No; warm pools hand out fresh sessions from a template | Fork a running sandbox with its disk |
| Docker and nested virtualization | Docker; nested virtualization on x64 Linux runners, not on ARM | Docker and nested virtualization on Linux; neither inside macOS sessions | Docker, root, systemd and /dev/kvm on every machine |
| Machines at once | Docs say Blacksmith imposes no concurrency limits | Pro runs 10 macOS or 30 Linux builds at once; dev tiers 1 to 5 VMs | 100 to 2,000 sandboxes by plan, with starts per minute limited |
| Desktop and computer use | Headless runners | VNC desktop on macOS sessions; an MCP server takes screenshots and controls it | 60fps Linux desktop with Chromium and computer use |
| Coding agents | Its own [code]smith agent; Testbox CLI in early beta for local agents | Claude Code started from the CLI in a dev session; others by warmup script | Seven agents preinstalled, driven from outside with a prompt, steer and events API |
| Reaching the machine | Opt-in debug SSH for the user who started the job; no ports or URLs | SSH, VNC and a web terminal; no public URL for a port | HTTPS URLs on up to 50 ports, raw TCP and a dedicated IP |
| Mobile build pipeline | Runs your GitHub Actions workflows, with Docker layer caching and sticky disks | Workflows, code signing, build cache, release management and over-the-air updates | None built in; you install the tools you need |
| Regions and hosting | Ashburn, Phoenix, Amsterdam and Frankfurt; managed only | US, Ireland, Frankfurt, Singapore and Sydney; can run in your own AWS account or on your own hardware | EU only (Germany, Finland, France); managed only |
Every feature Battleships tracks (43)
| Feature | Blacksmith | Bitrise | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Yes | Yes |
| Nested virtualization | Yes | Yes | Yes |
| Root | Yes | Yes | Yes |
| Systemd | No | No | Yes |
| Desktop GUI | No | Yes | Yes |
| Browser | Yes | Yes | Yes |
| Computer-use API | No | Yes | Yes |
| SSH | Yes | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | No | Yes | Yes |
| Automatic snapshots | No | No | Yes |
| Fork/clone | No | No | Yes |
| Live fork (no pause) | No | No | Yes |
| Memory fork | No | No | No |
| Custom image (Docker or snapshot) | No | Yes | Yes |
| ≥24 h sessions | Yes | No | Yes |
| Idle auto-stop | Yes | Yes | No |
| Wake on request | No | No | No |
| HTTPS preview URLs | No | No | Yes |
| Raw TCP inbound | No | No | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | No | No | No |
| Secret proxy | No | No | Yes |
| Secret proxy for any API | No | No | Yes |
| Preinstalled agents | No | Yes | Yes |
| Agent harness API | No | Yes | Yes |
| MCP server | No | Yes | No |
| GPU | No | No | No |
| Windows | Yes | No | No |
| Arm64 | Yes | Yes | No |
| Self-hosting | No | Yes | No |
| BYOC | No | Yes | No |
| Open source | No | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | Not published | Not published | Yes |
| Usage per sandbox (API) | Yes | No | Yes |
| Audit logs | Not published | Not published | No |
| SSO | No | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | No | No | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
There is no comparable measurement for Blacksmith or Bitrise: neither was part of the same CPU benchmark run, so we do not compare their speeds. boat did 26.69 runs per second on the StarSling hpc-sandbox-benchmarks Node.js loop at 4 vCPU / 8 GB, on dedicated AMD Ryzen 9 9950X hosts.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Blacksmith and Bitrise have no published run in this suite yet, so there is no like-for-like number to compare.
Pricing in five scenarios
Each bill is priced from the providers' public price lists by the open Battleships engine, with the cheapest plan that runs the scenario.
| Scenario | Blacksmith, a month | Bitrise, a month | boat, a month |
|---|---|---|---|
| One coding agent, workdays 4 vCPU / 8 GB, 50 GB disk, 8 hours a day, 22 days a month, files kept between days | $36 · Pay-as-you-go · with limits | $260 · Pro · with limits | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $207 · Pay-as-you-go · with limits | $119 · RDE Pro · with limits | $26 · $20/mo |
| 50 agents in parallel 50 machines of 4 vCPU / 8 GB at once, 8-hour sessions, 1,100 sessions a month, Docker inside | $2,364 · Pay-as-you-go · with limits | $2,309 · Pro · with limits | $317 · $20/mo × 3 seats |
| Sandboxes for your users 2 vCPU / 4 GB, 30,000 sessions of 10 minutes a month, up to 300 at once | $663 · Pay-as-you-go · with limits | $812 · Pro · with limits | $200 · $100/mo × 2 seats |
| 1,000 short jobs at once 2 vCPU / 4 GB, 1,000 at once, 3 minutes each, 200,000 jobs a month | $1,488 · Pay-as-you-go · with limits | $1,538 · Pro · with limits | $2,000 · $2000/mo · with limits |
Blacksmith: Blacksmith bills per minute of job time, scaled by vCPU and OS: Ubuntu x64 is $0.004 a minute for 2 vCPU and ARM $0.0025, with 3,000 free minutes a month. Sticky disks cost $0.50 per GB a month.
Bitrise: Bitrise CI is sold by plan: Starter is a flat fee with unlimited minutes on Medium machines, and Pro adds per-minute machine time and a build allowance on top of its fee. Remote Dev Environments charge a base fee with included minutes, then per minute up to a monthly cap per OS.
Bitrise: Plans start at $20 a month, and the whole fee is usage credit spent per second while a sandbox runs. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
None of the agent scenarios fit either service cleanly, because both are CI runners. On Blacksmith only sticky disk folders survive between jobs, so packages installed anywhere else are gone. On Bitrise Pro, builds stop at 3.5 hours and only 10 run at once, so 50 agents in parallel and 300 user sandboxes do not fit; for one agent running all month its dev environments fit better, at $119 against $207 on Blacksmith. For 1,000 short jobs at once, boat's $2,000 plan queues starts above 90 per minute.
| Scenario | Blacksmith | Bitrise | boat |
|---|---|---|---|
| One coding agent, workdays |
|
| None that bite |
| One agent that never stops |
|
| None that bite |
| 50 agents in parallel |
|
| None that bite |
| Sandboxes for your users |
|
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Blacksmith when
your CI runs on GitHub Actions and you want faster jobs by changing one label, with no concurrency limit and Linux, Windows or macOS runners.
- A drop-in for GitHub Actions. If your CI already lives in GitHub Actions, you switch by changing one runner label and keep your workflows.
- No concurrency limit. Blacksmith's docs say it imposes no concurrency limits, so a big test matrix can start all at once.
- Windows runners and big Linux machines. Teams that build for Windows get Windows Server 2025 runners, and Ubuntu x64 runners go up to 32 vCPU and 128 GB.
Use Bitrise when
you build and ship iOS or Android apps, want Macs with iOS simulators for people or agents, or must run in Asia Pacific or your own AWS account.
- A full mobile CI/CD pipeline. If you ship iOS or Android apps, Bitrise handles builds, code signing, caching, store releases and over-the-air updates.
- Macs an agent can drive. Its dev environments rent Apple silicon Macs with iOS simulators and a desktop an agent controls through an MCP server.
- More regions and self-hosting. It runs in the US, Europe, Singapore and Sydney, and can run inside your own AWS account or on your own hardware.
Where boat fits
Blacksmith and Bitrise are CI services, and both are good at running builds. If what you are really running is agents, the machine has to outlive a job, keep its files and be reachable from outside. That is what boat is built for: a full Linux VM per agent that you start by API and drive from outside.
A machine that outlives the job
A Blacksmith microVM is destroyed when its job ends and a Bitrise CI build stops at 210 minutes and rolls back. Bitrise dev sessions last longer but keep one disk with no backup. boat has no session cap and saves the whole disk every minute.
Agents driven from outside, keys kept out
Blacksmith starts machines from GitHub workflows and Bitrise starts Claude Code in a terminal, so many agents means scripting each session. boat has a prompt, steer and events API, and its credentials proxy keeps real keys out of the VM, where both put secrets inside.
Show what the agent built
Neither gives a public URL for a port: Blacksmith offers debug SSH and Bitrise SSH or VNC, so a preview needs your own tunnel. boat serves HTTPS on up to 50 ports with raw TCP, and you can fork a running sandbox to try two ideas.
Use boat when what you are running is agents: a full Linux VM you start by API, that keeps its disk, hosts what it builds, shows a desktop and runs coding agents you drive from outside. Compare it one to one: boat vs Blacksmith and boat vs Bitrise.
Questions people ask
Is Blacksmith cheaper than Bitrise?
It depends on the job. One coding agent on workdays comes to $36 a month on Blacksmith and $260 on Bitrise, but one agent running all month is $119 on Bitrise against $207 on Blacksmith. boat comes to $20 and $26 a month for those two.
Which is faster, Blacksmith or Bitrise?
We have no comparable CPU measurement for either, so we do not rank their speed. Blacksmith says its runners use fast gaming CPUs. boat did 26.69 runs per second on the StarSling Node.js benchmark at 4 vCPU / 8 GB.
Can Blacksmith or Bitrise run Docker?
Both run Docker on Linux. Blacksmith supports nested virtualization on x64 Linux runners but not on ARM, and Bitrise macOS sessions cannot run Docker or Android emulators. boat has Docker, systemd and /dev/kvm on every machine.
Can I run AI coding agents on Blacksmith or Bitrise?
Partly. Bitrise dev environments start Claude Code from its CLI on a persistent disk, and Blacksmith has a Testbox CLI in early beta, with its Sandboxes product marked coming soon. boat ships seven agents preinstalled that you drive through an API.
Which one supports macOS and iOS builds?
Both have Apple silicon Macs. Bitrise is built around mobile, with iOS simulators, code signing and store releases, while Blacksmith runs macOS jobs from GitHub Actions. boat runs Linux only.
Is boat SOC 2 compliant?
SOC 2 is in progress. We're open about where we stand: live status at status.ascii.dev and our data retention policy at docs.boat.dev/data-retention.
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