E2B alternatives in 2026

01Why teams look for E2B alternatives

• GPUs. E2B sandboxes are CPU only, BYOC included [12].
• Laptops and air-gapped sites. E2B Embed needs a Linux machine with hardware virtualization, and an air-gapped install is not documented [3].
• Lifetime. Continuous running time is capped at 1 hour on Hobby and 24 hours on Pro [16].
• Audit and SSO. E2B documents a 7-day lifecycle events API, not a dedicated audit log, and does not document its SSO protocol [10] [11].

02E2B alternatives at a glance

Listed in no order of merit. Each line sums up the comparison page it links to, where every fact cites that vendor's own pages.

03The short verdict

Choose E2B if

• you want a managed sandbox cloud with five regions and BYOC on AWS, GCP or Azure [2] [4];
• you need a SOC 2 Type II report and a pen test report today [1];
• you want the integrations E2B documents for many agent frameworks and tools [13];
• you need up to 1,100 concurrent sandboxes on Pro [15].

Choose kosa8 if

• sandboxes must run on developers' laptops (Mac, Linux or Windows through WSL2) as well as servers [18];
• you need an air-gapped site with a signed offline licence [18];
• you want API keys added by an egress broker so the sandbox never holds them [26];
• you want a hash-chained audit log anyone can verify, and an organization-wide freeze [22] [24].

04E2B and kosa8, feature by feature

Bracketed numbers point to the sources. "Not documented" means the vendor's own pages did not say on 2026-11-14; it does not mean the feature is missing.

05Where E2B is stronger

• Compliance paperwork. E2B has a SOC 2 Type II report and a pen test report [1]; kosa8 has neither yet [26].
• Managed regions and BYOC. Five regions across GCP and AWS, and BYOC on three clouds [2] [4]. kosa8 Cloud has two regions, and its BYOC joins KVM Linux servers you run [18].
• Ecosystem and scale. Many documented integrations [13] and up to 1,100 concurrent sandboxes on Pro [15]; kosa8 Cloud defaults to 20 [20].
• Network rules on a running sandbox. E2B changes egress rules live [8]; kosa8 fixes them at create, and kosa8 Cloud has no egress setting yet [21] [22].

06Where kosa8 is different

• Local first. kosa8 runs on a Mac, Linux or Windows (WSL2) laptop, not only on Linux servers [18].
• Rewind. kosa8 keeps a list of checkpoints and puts the machine back to any of them [19].
• Keys stay out, and the log can be checked. An egress broker adds keys on the way out; the hash-chained audit log verifies with one command [24] [26].
• Freeze. One call on kosa8 Cloud refuses new work, sleeps every sandbox and can suspend every key [22].

07Moving from E2B to kosa8

E2B's quickstart creates a sandbox, runs a shell line and kills it [13] [6]. kosa8 Cloud has the same shape.

E2B, from its docs:

from e2b import Sandbox

sandbox = Sandbox.create()  # Needs E2B_API_KEY environment variable
result = sandbox.commands.run('echo "Hello from E2B Sandbox!"')
print(result.stdout)
sandbox.kill()

The same on kosa8 Cloud (Python, pip install kosa8):

from kosa8 import Kosa8Cloud

cloud = Kosa8Cloud()  # reads KOSA8_API_KEY
box = cloud.sandboxes.create(template="python", sleep_after_s=600)
r = box.exec(["python3", "-c", "print('hello')"])
print(r.exit_code, r.stdout)
box.delete()

• E2B_API_KEY becomes KOSA8_API_KEY.
• commands.run('a shell line') becomes exec(['sh', '-c', 'a shell line']); result.stdout stays r.stdout.
• sandbox.kill() becomes box.delete(); pause() becomes box.sleep() [19].
• sandbox.fork() becomes POST /v1/sandboxes/{id}/fork with n up to 100, or kosa8 fork locally [19].
• E2B's allowOut list maps to --egress-allow on a local sandbox [21].
• Each kosa8 Cloud exec runs in a fresh container on the sandbox's disk: files under /workspace persist between commands, background processes do not. A buffered exec stops at 90 seconds; send stream: true for longer commands [19].
• Templates today are base (Alpine), python (Python 3.12) and node (Node.js 22) [19].
• An organization runs up to 20 sandboxes at once on kosa8 Cloud unless you ask for more [20].

08Questions

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