E2B vs Fly.io Sprites
Answer in brief
Choose E2B for code interpreters and short-to-medium-lived agent tasks that need microVM isolation, with an open-source self-host path; choose Fly.io Sprites for long-running, stateful agent computers that should cost nothing while idle. E2B uses Firecracker microVM isolation and is open source; Fly.io Sprites uses MicroVM isolation.
E2B vs Fly.io Sprites at a glance
| Attribute | E2B | Fly.io Sprites |
|---|---|---|
| What it is | Open-source cloud sandboxes for AI agents, each a Firecracker microVM, with pause/resume, snapshots and forking. | Persistent, hardware-isolated Linux computers for AI agents with a durable 100 GB disk, checkpoints, and no compute charges while idle. |
| Isolation | Firecracker microVM with its own kernel per sandbox | Dedicated microVM with hardware-level isolation (Fly docs); reported to be Firecracker-based |
| Open source | Yes (Apache-2.0) | No (SDKs MIT) |
| Self-host / BYOC | Yes / Yes | No / No |
| SDKs | Python, JavaScript/TypeScript | JavaScript/TypeScript, Go, Python, Elixir |
| Cold start (vendor claim) | Not documented | Warm wake 100–500 ms with processes preserved; cold wake 1–2 s (vendor docs) |
| Max session | Up to 1 hour continuous (Hobby), 24 hours (Pro) or custom (Enterprise); pausing resets the clock and paused sandboxes are kept until deleted | No lifetime limit — a Sprite persists until destroyed and sleeps after ~30 s idle |
| Persistence | Pause/resume preserves filesystem and memory; snapshots of running sandboxes, forking from a snapshot, filesystem-only snapshots, auto-resume and volumes (beta) | 100 GB durable disk per Sprite that survives sleep; copy-on-write checkpoints (~1 s) with restore; memory preserved on warm pause |
| GPU | No — sandboxes are CPU-only | No GPU option documented |
| Networking | Internet on by default; can be disabled or restricted with allow/deny lists of IPs, CIDRs and domains; public sandbox URLs for exposed ports; custom domains and published egress IPs | HTTPS URL per Sprite (org-private by default); outbound open by default with optional DNS-based domain allow/deny policy; connectors broker API credentials |
| Pricing | Per second: $0.000014 per vCPU-second (~$0.050/vCPU-hour) + $0.0000045 per GiB-second (~$0.016/GiB-hour). Pro plan $150/month plus usage; Enterprise from $3,000/month | Per second, compute only while active: $0.0385 per CPU-hour + $0.021875 per GB-hour memory; storage billed while idle |
| Compliance | SOC 2 Type II; HIPAA BAA and DPA available on request | Fly.io is SOC 2 Type 2; HIPAA BAA and DPA available (company-wide) |
| Best for | Code interpreters and short-to-medium-lived agent tasks that need microVM isolation, with an open-source self-host path | Long-running, stateful agent computers that should cost nothing while idle |
Verified November 8, 2026 from each provider’s documentation. Cold-start figures are vendor claims, not our measurements.
Which should you choose?
Choose E2B if…
- You want the most widely integrated agent sandbox, with a large ecosystem of examples
- You need Firecracker microVM isolation for untrusted multi-tenant code
- You want an open-source codebase you can self-host or run via BYOC
- You want ready-made code-interpreter and desktop SDKs
Choose Fly.io Sprites if…
- You want a persistent computer per agent or per user
- Your agents are idle most of the time and you want to pay only for active compute
- You want fast checkpoints and rollback
- You want Elixir or Go SDKs
Both are worth piloting with your own image and region. See the full E2B profile and Fly.io Sprites profile, or the complete comparison.
Frequently asked questions
Is E2B or Fly.io Sprites better for AI agents?
Neither is better for every workload. E2B is best for code interpreters and short-to-medium-lived agent tasks that need microVM isolation, with an open-source self-host path. Fly.io Sprites is best for long-running, stateful agent computers that should cost nothing while idle.
Which is open source, E2B or Fly.io Sprites?
E2B is open source (Apache-2.0); Fly.io Sprites is not.
How do E2B and Fly.io Sprites isolate code?
E2B: Firecracker microVM with its own kernel per sandbox. Fly.io Sprites: Dedicated microVM with hardware-level isolation (Fly docs); reported to be Firecracker-based.
Sources
Cite this page
Agent Sandboxes. (2026). E2B vs Fly.io Sprites. agentsandboxes.org. Last reviewed November 8, 2026. https://agentsandboxes.org/compare/e2b-vs-fly-sprites/
Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.