Open-source AI infrastructure

E2B Alternatives in 2026

Alternatives to E2B for running AI-generated code, compared on isolation primitive, whether self-hosting is real, how concurrency is priced, and which projects are…

Concurrency and session length are pricing tiers

E2B caps concurrent sandboxes at 20 on Hobby and 100 on Pro, purchasable to 1,100, with sessions capped at 1 hour and 24 hours respectively. Agent workloads are bursty, so the concurrency ceiling is usually the first constraint teams hit, and hitting it is a procurement conversation rather than a scaling one.

Check the commit history, not the star count

Daytona carries 71,871 GitHub stars and a README stating that as of June 2026 core development moved to a private codebase and the repository will receive no further updates, fixes or releases. Check the LICENSE file too: it was Apache-2.0 at the first commit in February 2024, AGPL-3.0 from April 2025, and deleted outright on 23 June 2026, so GitHub now reports the repository licence as none and the last open release, v0.190.0, is the AGPL-3.0 tag the README points forks at. For a sandbox, whose entire job is to be a security boundary, running an unmaintained snapshot is a serious position. Their hosted product is unaffected and is genuinely fast, documenting sub-90ms starts.

The isolation primitive decides more than the feature grid

For untrusted, model-generated code, containers alone are a weaker boundary than most teams assume, since container escapes are a recurring vulnerability class. MicroVMs and gVisor are where this category has converged: E2B and Everstack use Firecracker, Modal uses gVisor. Daytona is the case for pinning it down, because its documentation says default sandboxes are Linux containers while its README claims a dedicated kernel. If a vendor is vague about which primitive they use, settle that before reading anything else on their page.