What is it
CPU-Hour Pricing is a billing unit where customers are charged for the CPU time their workloads consume, typically measured in vCPU-seconds or vCPU-hours.
A vCPU-hour is the product of two numbers: how many CPU cores a workload reserves and how long it holds them. Run 2 vCPUs for 30 minutes and you have consumed 1 vCPU-hour. The unit exists because, on serverless and sandbox platforms, the customer is buying compute work — not a reserved server that sits powered on whether or not it is doing anything. Billing CPU time, rather than wall-clock uptime or a proxy like requests, aligns the invoice with the actual work performed.
The modern refinement is active CPU billing — metering only the milliseconds the CPU is genuinely executing code, not the time a process spends idle waiting on I/O. Vercel is the canonical example: its Fluid Compute model, switched to Active CPU billing in June 2025, charges only for CPU-active milliseconds — $0.128 per CPU-hour on the Pro plan. For an AI inference call that spends 50ms computing and 950ms waiting on the model, Vercel bills the 50ms and cites up to 90% savings on I/O-heavy workloads — the first Active CPU billing model from a major PaaS provider.
CPU-hours are most common among compute-execution platforms: serverless functions, code-interpreter sandboxes, distributed-training clusters, and on-demand GPU clouds where CPU is the cheap companion meter. Modal and E2B bill CPU per vCPU-second alongside their memory and GPU lines, BentoML meters a plain CPU instance at $0.00001322/sec, while CoreWeave and Nebius are large-scale GPU cloud providers where CPU billing completes the resource picture for customers running H100 and A100 clusters.
How it works
The core formula is identical everywhere: CPU cost equals allocated vCPUs multiplied by the time those cores are held, times a per-vCPU rate. The variation is in what counts as “held” — whether the meter runs on wall-clock uptime or only on active execution — and in how finely time is measured.
| Dimension | What it controls | Example from this corpus |
|---|---|---|
| Active vs. wall-clock | Whether idle (I/O-waiting) time is billed | Vercel’s Active CPU bills only execution milliseconds; most others bill per-second while the sandbox is alive |
| Rate granularity | How finely time is measured | E2B, Modal, and Trigger.dev meter per second; CoreWeave and Nebius quote per-hour rates |
| Bundling | Whether CPU is a standalone line or folded into credits | Modal and E2B list a discrete CPU rate; Anyscale and Lightning AI denominate it in credits (1 credit ≈ $1) |
| Pairing | Which other meters ride alongside | Modal pairs CPU-hours with memory and GPU-hours; GitLab pairs compute time with CI/CD pipeline minutes |
The per-vCPU rates cluster tightly at the bottom of each rate card. Modal bills a physical CPU core at $0.0000131 per second (about $0.047 per hour, with a 0.125-core minimum), E2B bills $0.000014 per vCPU-second (about $0.05 per hour, scaling linearly — 2 vCPUs cost $0.000028/s, 8 vCPUs cost $0.000112/s), and BentoML’s cpu.1 instance is $0.00001322 per second. The CPU line is almost always the least expensive meter; the cost in a real bill comes from memory, GPU, or runtime, not the cores.
Unit math: A sandbox holding 4 vCPUs for 30 minutes consumes 4 × 0.5 = 2 vCPU-hours. On E2B that compute line is ~2 × $0.05 = $0.10 ($0.000056/s × 1,800s); on Modal a comparable 4-core run is ~2 × $0.047 = $0.094 — before memory, GPU, or storage charges are added.
Active CPU billing changes the numerator without changing the formula. On Vercel, a Fluid Compute function that runs for one wall-clock second but only executes for 50ms is billed for 0.05 CPU-seconds, not 1 — so the same invocation pattern can cost a fraction of what a wall-clock meter would charge. Picking the right compute meter is a metric-selection decision as much as a packaging one; see the guide on choosing the right usage metric, and model a blended serverless bill with the Vercel pricing calculator.
Companies using this
Sixteen companies in the corpus meter CPU time, spanning serverless and sandbox platforms (Vercel, Modal, E2B, Trigger.dev, Novita AI), GPU clouds where CPU is the companion meter (CoreWeave, Nebius), ML platforms that fold CPU into inference or credit billing (BentoML, Hugging Face, LangChain, Anyscale, Lightning AI, OpenPipe, Together AI), and workflow or database contexts (GitLab, Qdrant).
Patterns observed
On every platform in this corpus the CPU line is an order of magnitude below GPU and often below memory. BentoML, CoreWeave, and Nebius all follow the same structure — the GPU is the primary cost driver, and CPU is billed to complete the resource picture for CPU-bound workloads. BentoML’s cpu.1 instance runs $0.00001322/sec against a T4 at $0.00014198/sec and an H100 at ~$2.65/hr; Nebius lists CPU-only instances from $0.05/hr (Intel Ice Lake) and $0.10/hr (AMD EPYC Genoa) against an on-demand H100 at $3.85/GPU/hr. CoreWeave and Nebius both run large-scale GPU cloud infrastructure where individual A100 and H100 instances dominate customer bills; CPU is present on every rate card but rarely the primary optimization target. The pattern holds across the GPU cloud cluster: a buyer running a training job on CoreWeave or Nebius will scrutinize GPU and networking costs far more carefully than the CPU line sitting at the bottom of the same invoice.
Per-second is the real granularity behind the “CPU-hour” label, and the distinction matters most for short workloads. Modal and E2B bill per vCPU-second; Trigger.dev bills per compute-second for serverless job execution, from $0.0000169/sec (Micro, 0.25 vCPU) to $0.00068/sec (Large 2x, 8 vCPU); Novita AI and Lightning AI both meter per second and only quote hourly rates for readability. The “CPU-hour” label exists so buyers can reason about cost, but these platforms meter at second or millisecond resolution because agent and sandbox workloads are short — a code-execution sandbox that completes in eight seconds should not round up to an hour, and it does not on any of these platforms. The per-second granularity is not a premium feature; it is the baseline expectation for any platform targeting short-lived compute jobs.
Active CPU as a differentiator sets Vercel apart from every other company in this set. Vercel is the only platform that meters execution time rather than wall-clock uptime, and it leans on that as a marketing wedge, citing up to 90% savings on I/O-heavy workloads. GitLab’s CI/CD compute, charged per CI minute, is also execution-time-based by nature — a pipeline only runs when it is running, so idle time between jobs does not accumulate. Trigger.dev’s serverless job billing similarly charges for active execution; a background job queued but not yet running, or paused on a checkpointed wait, accrues no compute cost. These three show that active-execution billing is not unique to web-function platforms — any execution context where jobs start and stop cleanly is a candidate for it.
Credit denomination and inference bundling hide the CPU rate for a significant portion of this corpus. Anyscale denominates CPU-only compute at $0.0135/hr in Anyscale Compute Units where $1 ACU literally equals $1, and Lightning AI draws per-second CPU and GPU usage from a credit pool where one credit is roughly a dollar. Together AI, OpenPipe, Hugging Face, and LangChain (for managed deployments) all wrap compute into an inference or platform API. Hugging Face’s inference endpoints bill per hour of deployed instance, but the CPU is bundled into the instance type — a buyer pays for the instance, not for its constituent vCPUs separately. For these companies the CPU-hour is a real cost the vendor absorbs and passes through in the credit or instance price, but it is not a line the buyer ever negotiates or optimizes against directly.
Counterexamples & variants
Vercel’s Active CPU billing carries a catch that never surfaces in a wall-clock model: predictability. Because the meter tracks execution profile rather than uptime, a workload’s cost depends on how compute-heavy it actually turns out to be — harder to forecast from a plan card than a flat per-second rate, and the price of subtracting idle time.
The credit-denomination structure (Anyscale, Lightning AI) makes the CPU rate invisible rather than merely cheap: a buyer comparing either platform to Modal must first translate a credit-denominated rate back into a per-vCPU figure before the numbers mean anything. That opacity is the trade for smoothing GPU and CPU onto one currency.
OpenPipe and Together AI show where the CPU-hour stops being a true compute meter. Both are token-first inference platforms; CPU-hours appear only at the edges — OpenPipe bills hosted inference “per-token or by hourly compute units,” and Together AI exposes them mainly through its Code Sandbox and dedicated-endpoint plumbing rather than a primary SKU. Here the CPU-hour is a cost the vendor absorbs, not one the buyer optimizes against.
Qdrant is the vector-database variant: rather than per-query pricing, Qdrant Cloud meters vCPU + RAM + storage hourly, so the cluster’s CPU allocation is a first-class billing dimension — even though a permanent free 0.5-vCPU tier exists and the pricing page never prints a dollar-per-vCPU-hour figure.
What this means for buyers vs vendors
For buyers
Ask whether the meter is active CPU or wall-clock — it is the single biggest cost variable on this page. An I/O-bound workload (an AI proxy, a database-backed API) can cost far less under Vercel’s Active CPU billing than under a wall-clock meter that charges every second the process waits. Then get the per-vCPU rate in a comparable unit; a platform that bundles CPU into a credit pool or instance price will require you to back-calculate the implied cost before any comparison is honest. And scrutinize the GPU and memory rates harder than the CPU line, because that is where the real bill lives.
For GPU-cloud procurement, model total cluster cost — GPU plus networking plus storage — rather than the per-vCPU rate: on CoreWeave and Nebius the CPU line is a rounding term next to the GPU. It matters mainly when a workload has significant CPU-only pre- or post-processing running separate from GPU inference.
For ML-platform and credit-pool billing, the meaningful comparison is between instance configurations (memory-optimized vs. compute-optimized), whether the platform supports scale-to-zero so idle endpoints accrue nothing (BentoML advertises this explicitly), and — for credit platforms — how many effective CPU-hours a dollar of credit actually buys.
For vendors
CPU-hour billing fits any product that runs customer code on shared compute — serverless functions, sandboxes, training clusters, on-demand instances. It requires per-second (or finer) metering and the ability to attribute core-time to a tenant, which is heavier than counting requests; the underlying metering and aggregation problem is covered in the guides on tracking and metering usage events and aggregation methods for usage-based billing. The defensible move is active-CPU billing: metering execution rather than uptime, as Vercel does, is a genuine customer-friendly innovation that doubles as marketing copy.
The packaging decision is whether to expose a discrete per-vCPU rate (transparent, like Modal, E2B, and BentoML) or fold CPU into a credit currency or instance price (simpler ladder, like Anyscale, Lightning AI, and Hugging Face) — the former wins trust with cost-conscious engineers, the latter smooths multi-resource pricing into one number. For platforms that adopt credit packaging, the operational risk is that the CPU-hour rate disappears into the credit price, making cross-vendor comparison harder and potentially obscuring vendor margin from sophisticated buyers.
Workflow-compute contexts — CI/CD pipelines and serverless background jobs, as GitLab and Trigger.dev demonstrate — are a natural fit for execution-time billing because the job boundary is well-defined: a pipeline starts, runs, and ends, with no ambiguity about what counts as active execution, and a checkpointed wait consumes nothing. For vendors building in these categories, per-minute or per-second execution billing is already the buyer expectation; the differentiation opportunity is in free-tier generosity and cold-start latency, not in the billing unit itself. For the broader trade-offs, see the introduction to usage-based pricing.
| Company | Product | Pricing model | Billing units | Free tier | Verified |
|---|---|---|---|---|---|
| Anyscale | Managed Ray platform for distributed AI training, inference, and batch processing (RayTurbo, Anyscale Compute Units) | Yes | 2026-05-29 | ||
| BentoML | BentoCloud — managed model-serving & inference platform | Yes | 2026-06-15 | ||
| CoreWeave | GPU cloud & AI compute infrastructure | No | 2026-06-15 | ||
| E2B | Open-source cloud sandboxes for AI agents — secure, isolated micro-VMs that run LLM-generated code, coding agents, and computer-use workflows | Yes | 2026-06-02 | ||
| GitLab | AI-native DevSecOps platform (source control, CI/CD, security, agents) | Yes | 2026-06-21 | ||
| Hugging Face | AI model hub, inference endpoints & compute | Yes | 2026-06-15 | ||
| LangChain | Agent orchestration frameworks + LangSmith platform | Yes | 2026-06-10 | ||
| Lightning AI | Cloud GPU/CPU Studio compute platform for building, training, and serving AI models, billed by the second with a credit pool. | Yes | 2026-06-02 | ||
| Modal | Serverless compute and GPU platform — per-second billing for Python functions, batch jobs, and model serving | Yes | 2026-05-29 | ||
| Nebius | AI cloud & GPU compute infrastructure | No | 2026-06-15 | ||
| Novita AI | Pay-as-you-go AI cloud: 200+ model inference APIs, on-demand GPUs, and per-second agent sandboxes under one API | Yes | 2026-07-06 | ||
| OpenPipe | OpenPipe fine-tuning and hosted inference platform (small specialized models / RL for agents) | Yes | 2026-06-04 | ||
| Qdrant | Open-source vector database + Qdrant Cloud | Yes | 2026-06-09 | ||
| Together AI | AI Acceleration Cloud — serverless inference, dedicated endpoints, GPU clusters, Code Sandbox, fine-tuning | Yes | 2026-06-30 | ||
| Trigger.dev | Background jobs and workflow orchestration for developers | Yes | 2026-06-16 | ||
| Vercel | Frontend cloud platform | Yes | 2026-07-06 |
Explore this theme in the knowledge graph
FAQ
What is CPU-hour pricing?
CPU-hour pricing charges for the CPU time a workload consumes, usually measured in vCPU-seconds or vCPU-hours. It is calculated as allocated CPU cores multiplied by the time those cores are held, so 2 vCPUs for 30 minutes equals 1 vCPU-hour.
What is the difference between CPU-hour billing and wall-clock billing?
Wall-clock billing charges for every second a process is alive, including idle time waiting on I/O. Active-CPU billing, like Vercel's Fluid Compute, only meters the time the CPU is actually executing code. For an I/O-heavy AI call, that can cut the bill by 90% or more.
How much does a CPU-hour cost?
The CPU line is usually the cheapest meter. Modal bills a physical core at $0.0000131 per second (about $0.047 per hour), E2B bills $0.000014 per vCPU-second (about $0.05 per hour), BentoML bills a cpu.1 instance at $0.00001322 per second, and Anyscale's CPU-only ACU is $0.0135 per hour. GPU rates on the same platforms are hundreds of times higher.
Why do platforms bill per vCPU-second instead of per hour?
Agent, sandbox, and serverless workloads are often short — seconds to a few minutes. Modal, E2B, and Trigger.dev meter per second and only express rates in hour terms for readability, so a 5-minute task is billed for exactly 5 minutes rather than rounded up to an hour.
Which companies use CPU-hour pricing?
In this corpus, Vercel, Modal, E2B, BentoML, CoreWeave, GitLab, Hugging Face, LangChain, Nebius, Novita AI, Anyscale, Lightning AI, OpenPipe, Qdrant, Trigger.dev, and Together AI meter CPU time. Vercel, Modal, and E2B are the cleanest active-CPU or per-second examples; CoreWeave and Nebius are GPU clouds where CPU is the companion meter.
Related billing units
- Credit-Based BillingA billing unit where customers pre-purchase or are allocated a pool of credits that deplete as they use the product, often at variable rates per feature.
- Token-Based PricingA billing unit common in LLM and AI products, where customers are charged per input and output token processed.
- Per-Seat PricingA billing unit where the vendor charges a fixed fee per named user, regardless of how much each user consumes.
- Per-Resolution PricingA billing unit unique to AI customer-support products, where the vendor charges only when an AI agent resolves a customer issue without escalation.
- Bandwidth-Based PricingA billing unit where customers are charged per gigabyte of data transferred out of the platform.
- Per-Function-Invocation PricingA billing unit where customers are charged per serverless function invocation, often combined with a separate compute-time charge.
- GB-Hour PricingA billing unit where customers are charged for the memory their workloads consume over time, measured in gigabyte-hours.
- GPU-Hour PricingA billing unit where customers are charged for GPU time consumed, typically measured per-second or per-hour by GPU type.
- Per-API-Call PricingA billing unit where customers are charged per API request, regardless of payload size or processing time.
- Per-GB Storage PricingA billing unit where customers are charged per gigabyte of data stored on the platform per month.
- Media-Minute PricingA billing unit where customers are charged per minute of audio or video processed — used by speech, voice, and video AI vendors.
- Per-Request PricingA billing unit where customers are charged per request served — the generic meter for inference endpoints, search, scraping, and browser infrastructure.
- Per-Event PricingA billing unit where customers are charged per event ingested — the native meter of observability and billing-infrastructure platforms.
- Vector Storage PricingA billing unit where customers are charged for vectors stored or indexed — the storage dimension of vector database pricing.
- Per-Character PricingA billing unit where customers are charged per character of text processed — the standard meter for text-to-speech and translation.
- Per-Document PricingA billing unit where customers are charged per document processed or generated — common in AI writing, SEO, and document-intelligence tools.
- Per-Page PricingA billing unit where customers are charged per page crawled, parsed, or rendered — the meter for web scraping and document parsing.
- Per-Transaction PricingA billing unit where customers are charged per financial or billing transaction processed — the meter of billing and accounting platforms.
- Active-User PricingA billing unit where customers are charged per monthly or daily active user rather than per provisioned seat.
- Per-Task PricingA billing unit where customers are charged per task an automation or agent executes — Zapier's historical unit, now spreading to AI agents.
- Per-Unit PricingA billing unit used by robotics, hardware AI, and some SaaS companies where the metered object is a physical or abstract 'unit' — a robot deployed, a device sold, or a defined deliverable.
- Workflow Execution PricingA billing unit where each end-to-end workflow or automation run is metered and billed, regardless of the compute steps it contains.
- Per-Message PricingA billing unit where each individual message or reply in a conversation is metered, common in AI chat and voice platforms.
- Per-Invoice PricingA billing unit used by billing infrastructure platforms where each invoice generated or processed is metered as the primary cost driver.
- Per-Action PricingA billing unit where each discrete action taken by an AI agent or automation is metered — common in browser automation and agentic workflow tools.
- Per-Image PricingA billing unit where each AI-generated image is metered, common in image generation APIs and multimodal AI platforms.
- Per-Conversation PricingA billing unit where each complete customer conversation — from first message to resolution — is metered as a single chargeable event.
- Per-Record PricingA billing unit where each data record processed, labeled, or extracted is metered — common in data platforms and web scraping services.
- Per-Word PricingA billing unit common in translation and localization platforms where the metered object is the word count of content processed.
- Per-Video PricingA billing unit where each AI-generated video is metered, common in video generation and synthetic media platforms.
- Milestone-Based PricingA billing unit used in drug discovery and biotech AI where payment is tied to achieving defined research milestones rather than time or compute consumed.
- Per-Outcome PricingA billing unit where payment is triggered by verified outcomes delivered — distinct from outcome-based pricing models, this refers specifically to 'outcomes' as a countable billing unit.
- Per-Datapoint PricingA billing unit where each individual data measurement or signal ingested is metered — common in cloud cost intelligence and ML evaluation platforms.
- Per-Interaction PricingA billing unit where each patient-agent or user-agent interaction is metered, common in healthcare AI and customer engagement platforms.
- Data Licensing PricingA pricing structure where access to proprietary datasets or data assets is licensed separately from the software or services, common in AI training data and clinical data platforms.
- Robot-Hour PricingA billing unit where each hour a robot or autonomous system operates is metered — the robotics equivalent of a GPU-hour.
- Per-Contact PricingA billing unit where each contact or lead in the database is metered, common in AI sales development and outbound automation platforms.
- Per-Mailbox PricingA billing unit where each connected email mailbox or sending account is metered, common in AI outbound sales and email automation platforms.
- Browser-Hour PricingA billing unit where each hour of headless browser compute time is metered, common in web scraping and browser automation platforms.
- Per-Generation PricingA billing unit where each AI-generated creative asset — image, video, or design — is counted as a 'generation' and metered accordingly.
- Per-Ticket PricingA billing unit where each customer support ticket handled by an AI agent is metered — common in AI customer service platforms.
- Per-Log PricingA billing unit where each LLM request log ingested or stored is metered — common in AI observability and evaluation platforms.
- Per-Trace PricingA billing unit where each distributed trace — a complete record of an LLM request chain — is metered, common in AI observability platforms.
- Per-IP PricingA billing unit where each IP address or proxy endpoint allocated is metered — used by web scraping proxy providers.
- Per-Device PricingA billing unit where each hardware device or endpoint connected to the AI platform is metered.
- Per-Case PricingA billing unit used in legal AI platforms where each case or matter processed by the AI is metered.
- Per-Report PricingA billing unit where each AI-generated report or analysis document is metered as a discrete output.