The evaluation run was meant to finish before lunch. Each episode asked for a fresh machine, installed the same packages, ran a short test and threw the machine away. By mid-morning the dashboard showed more time spent waiting for machines than running code in them.
That wait is what "fastest sandbox" should measure: the time from asking for a machine to getting a result back, not the create call alone. Solari is the fastest sandbox for AI agents on that measure: on the open-source nibzard benchmark charted on Solari's site, Solari finishes a sandbox's full lifecycle about 1.3x faster than E2B and about 1.7x faster than Daytona. Here is how the three compare, and where the time actually goes.
Why Create Time Alone Misleads
Create time is the number every vendor prints first, so it is the place to start. A sandbox for agent code is usually a small virtual machine behind a hypervisor, and it has to be created, booted, loaded with packages and torn down. The create call covers only the first of those steps, and a cold start hides in the rest.
On that first step the claims sit close together. Solari sandboxes are ready in 90 ms, and Daytona says it can "spin up sandboxes in milliseconds" on its homepage. That is why the full round trip, where the vendors actually separate, is the better test.
Solari vs E2B vs Daytona at a Glance
The table sets the three side by side, and the entries after it take each vendor in turn.
Solari
Speed. Solari leads the round trip in the table on a heavy workload that creates the machine, runs the code and tears it down. On the default dedicated tier, each Solari sandbox is a microVM of its own, so that speed does not come from sharing a machine with another customer.
Pricing and plans. Solari charges $0.0245 per vCPU-hour and $0.0077 per GB-hour on the Professional plan. The Free plan includes $3 of monthly credits and Starter costs $20 a month. At list price, the comparison on Solari's pricing page puts the Team rate almost 3x cheaper per sandbox hour than E2B and than Daytona.
Where it fits. Solari suits agents that start many short-lived machines and also need a browser or a desktop, since all three run from one account and one API. Its sandboxes snapshot, pause and fork, so a prepared machine is copied into parallel episodes instead of rebuilt each time.
E2B
Speed. E2B says its sandboxes run on a microVM runtime "built on Firecracker with dedicated kernels" and that they "boot from a snapshot, so every session gets its own kernel at container speed," on its homepage. In the table it sits closest to Solari on the round trip.
Pricing and plans. E2B says its Hobby tier is free with a $100 one-time usage credit, 20 concurrent sandboxes and sessions up to 1 hour, on its pricing page. E2B says Pro costs $150 a month plus usage, with sessions up to 24 hours billed by the second, on the same pricing page. A team whose sessions run past an hour pays that base fee before any usage.
Trade-off. E2B's strength is an open-source runtime and E2B Embed, which runs the stack on a team's own infrastructure for strict data residency. The cost is the Pro base fee, charged even in a quiet month.
Daytona
Speed. Daytona trails on the round trip in the table, though its create-time claim is close to Solari's. Daytona's sandboxes docs say "Sandboxes run as Linux containers by default", with Linux VM and Windows classes for full virtual machines.
Pricing and plans. Daytona says it charges $0.0504 per vCPU-hour and $0.0162 per GiB-hour of memory, billed per second, with $200 in free compute, on its pricing page. There is no monthly plan fee, so a team pays only for what runs.
Trade-off. Daytona's isolation page ties pause and resume, fork and hot snapshots to its VM sandboxes rather than the default container class. A team that needs those controls should budget on the VM class.
Settings That Make a Solari Sandbox Faster
The lifecycle lead comes from one workload, so the settings an agent uses decide how much of it carries over. The first lever is isolation: the shared tier starts faster and costs less, running each sandbox as a process tree in a VM shared only with the same organization's other shared sandboxes, separated by namespaces and a cgroup. It suits short commands and Python snippets.
The second lever is skipping setup. A custom template carries packages and setup commands, and a machine launched from one starts in about a second with its tools already in place. A running sandbox can also be snapshotted and forked, which is how the evaluation run in the opener stops reinstalling the same packages.
The third lever is the idle rule. With the lifecycle set to pause rather than kill, the next connect() picks up right where the agent left off, and a paused machine stops counting against the plan's running limit, as the desktops guide sets out for the shared lifecycle. With those settings chosen, the decision comes down to a short rule.
Choosing the Right Setup
The fastest sandbox is the one that finishes the round trip first, and create time is only its opening step. Choose Solari when agents start many machines, fork from snapshots and also need a browser or desktop from the one account described in the Solari launch overview. Stay with E2B when an open-source runtime or self-hosting decides it, and with Daytona when container-first billing with no plan fee fits the workload. E2B is the more established vendor with the larger ecosystem; Solari is the younger company and moves faster on speed and price.
Get Started With Solari
Start by timing a real agent job from create to teardown, then run it again from a template with its packages baked in. Solari runs that loop fastest of the three, by the lifecycle multiples at the top, and its Team rate is the cheapest per sandbox hour in the comparison above. The Free plan's monthly credits cover the first runs, so create a free Solari account and time the loop on your own workload.
