Fly Machines vs E2B
Low-level Firecracker VMs with an API and CLI for lifecycle and sizing. A fit for teams willing to build their own sandbox orchestration on top. Fly Machines does not publish comparable vCPU and memory rates, so no hourly price is compared; E2B lists $0.166 an hour for a 2 vCPU / 4 GiB sandbox.
Fly Machines against E2B, line by line
E2B baseline sourcesPrices are list prices for one hour of a 2 vCPU / 4 GiB sandbox: 2 × the vCPU rate + 4 × the memory rate. Each value links to the page it came from; not published means the vendor states no figure. How we compare.
Pick Fly Machines instead of E2B when
No field in this dataset favours Fly Machines over E2B. Choose it when its scope matches your constraint: Low-level Firecracker VMs with an API and CLI for lifecycle and sizing. A fit for teams willing to build their own sandbox orchestration on top.
Stay on E2B when
- pause has to keep running memory as well as files: E2B's pause saves both, and Fly Machines does not state memory state in our data.
- you need a SOC 2 report: E2B states Type II, and Fly Machines states none in our data.
- you want managed cloud, your own cloud account and self-hosting from one vendor: E2B offers all three, with BYOC on its Enterprise plan.
All Fly Machines facts
Source per value- Isolation Isolation technology the vendor states for each sandbox.
- Firecracker microVM 1
- Other isolation options Alternative runtimes the vendor offers besides the default (e.g. VM runtime, gVisor for GPU).
- Not published
- Deployment Managed cloud service, self-hosted software, or both.
- managed 1
- Billing basis What the meter counts: wall-clock allocated resources, active CPU only, requests/plan quota, session-hours, or free software.
- Not published
- vCPU price $/vCPU-hr Published on-demand CPU rate normalised to USD per vCPU-hour (per-second rates multiplied by 3,600; per-core rates divided by vCPUs per core where the vendor defines it). Lowest public tier, default region. 0 means the vendor states no separate CPU charge.
- Not published
- Memory price $/GiB-hr Published memory rate normalised to USD per GiB-hour (GB treated as GiB where the vendor does not distinguish). 0 means the vendor states memory is free.
- Not published
- Sandbox from $/sandbox-hr Smallest published per-sandbox hourly price, where the vendor publishes one.
- $0.003 2
- Paid plan from $/mo Cheapest paid platform plan fee (before usage).
- Not published
- Free tier A free plan, free monthly allowance or sign-up credit exists.
- Not published
- Free tier detail What the free tier or credit includes, as published.
- Not published
- Cold start ms Vendor-published create/boot time in milliseconds (a vendor claim, not our benchmark). Only filled when the vendor publishes a number; see startup_claim for percentile and conditions.
- Not published
- Resume time ms Vendor-published resume-from-pause/standby/snapshot time in milliseconds.
- Not published
- Startup claim The vendor's startup/resume wording with conditions, quoted or closely paraphrased.
- Existing Machines start and stop at subsecond speeds; image provisioning is separate. 3
- Max session length Longest single sandbox session by plan, as published.
- Not published
- Persistence / snapshots Filesystem state can be kept between runs (snapshots, persistent disks, volumes).
- Yes 2
- Pause / resume A sandbox can be paused, suspended, hibernated or put in standby and resumed later.
- Not published
- Memory state kept Pause/hibernate preserves running memory state, not only the filesystem.
- Not published
- Fork / branch A running or snapshotted sandbox can be cloned into new sandboxes.
- Not published
- GPU GPU sandboxes are offered.
- Not published
- Self-host Can run on your own hardware or cluster (open source or licensed).
- Not published
- BYOC / VPC Vendor-managed deployment inside your own cloud account.
- Not published
- Open source Core sandbox runtime is published under an open-source licence.
- Not published
- Licence Open-source licence of the runtime, if any.
- Not published
- SDKs / languages Official SDK languages (or supported execution languages where noted).
- REST API, flyctl 3
- Regions Published regions or region count.
- Not published
- Max vCPU per sandbox vCPU Largest published vCPU count per sandbox on any self-serve or enterprise plan.
- Not published
- Max memory per sandbox GiB Largest published memory per sandbox.
- 128 2
- Concurrency Published concurrent sandbox limits by plan.
- Not published
- SOC 2 SOC 2 status as stated by the vendor.
- Not published
- HIPAA Vendor offers HIPAA-compliant usage/BAA (on any plan).
- Not published
- 2 vCPU + 4 GiB per hour $/hr Hourly list price of one 2 vCPU / 4 GiB sandbox: 2 x the vCPU rate + 4 x the memory rate, from the two published rates. Left empty for self-hosted software and for vendors without both rates. Vendors that bill CPU only while busy (Vercel, Cloudflare, Upstash, Tensorlake, AWS AgentCore) cost less for idle agents than this shows.
- Not published
- Price vs E2B x E2B The 2 vCPU + 4 GiB hourly price divided by E2B's own ($0.1656 at $0.000014/vCPU-s and $0.0000045/GiB-s). Under 1 is cheaper than E2B.
- Not published
- Status Preview, experimental, beta, sunset or self-hosting caveats the vendor documents.
- Not published
- Pricing model
- usage
- From
- $0.003 sandbox-hour
- Pricing note
- Displayed shared-cpu-1x / 256 MB preset at $0.0030/hour; prices depend on region; volumes $0.15/GB-month, snapshots $0.08/GB-month; egress extra.
Sources
- fly.io/machines accessed 2026-11-11
- fly.io/pricing accessed 2026-11-11
- docs.fly.io/machines accessed 2026-11-11
Fly Machines in the E2B comparisons
- E2B alternatives with microVM or VM isolationWhich E2B alternatives give each sandbox its own kernel? 26 listed.
Compare with other E2B alternatives
All 41- AWS Lambda MicroVMs vs E2B no comparable hourly price, Firecracker microVM
- Azure Container Apps Dynamic Sessions vs E2B no comparable hourly price, Hyper-V
- Blaxel vs E2B no comparable hourly price, microVM
- Deno vs E2B no comparable hourly price, microVM
- Docker vs E2B no comparable hourly price, microVM
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