AI Summary
About
Weights & Biases (W&B) is the experiment-tracking layer that became an MLOps standard. Founded in 2018 by Lukas Biewald and Chris Van Pelt, its open SDK (wandb) — a few lines you drop into a training script to log metrics, hyperparameters, and artifacts — spread to over 1 million users including OpenAI, Meta, NVIDIA, and Toyota. The platform has since grown four product surfaces: W&B Models (experiment tracking, sweeps, registry, artifacts), W&B Weave (LLM observability, tracing, evaluations, and LLM-as-a-judge scorers for GenAI apps), W&B Serverless Inference (a per-token endpoint for 20+ open-weight models), and the new CoreWeave Sandboxes.
The headline corporate fact: on May 5, 2025, CoreWeave completed its acquisition of W&B for a reported ~$1.7 billion (W&B was last valued at $1.25B in 2023). The deal slots a developer-facing platform on top of CoreWeave’s GPU cloud, creating a path from raw compute to experiment tracking to inference. CoreWeave publicly committed to keeping the platform interoperable — customers can still use any infrastructure provider, deployment option, and foundation model — but the pricing now bundles CoreWeave Sandboxes and a first-party inference endpoint, both signs of the parent’s footprint.
For the most current information, visit Weights & Biases.
Pricing summary : How Weights & Biases’s pricing model works
W&B runs a freemium plan fee plus three usage meters. You pick a tier — Free ($0), Pro (starts at $60/month), or custom Enterprise — and each bundles a quota of seats, storage, and Weave data ingestion. The plan fee is only the floor; the variable bill comes from the meters.
The three things that actually scale your bill:
- Storage (GB) — model artifacts, datasets, and run history. Free includes 5 GB/mo, Pro 100 GB/mo, and overage runs $0.03/GB.
- W&B Weave data ingestion (GB) — the volume of logged LLM traces, evals, and monitoring data for GenAI apps. Free includes 1 GB/mo, Pro 1.5 GB/mo, and overage is $0.10/MB (i.e. ~$100/GB — far pricier than model storage, because it’s the live observability stream).
- W&B Inference (per token) — Serverless calls to 20+ open-weight models, billed per token in arrears (Pro ships a $5/mo credit).
Seats sit alongside these: Free allows up to 5 model seats, Pro up to 10. The legacy W&B Models meter — “tracked hours” (cumulative compute hours of logged training) — still surfaces in the academic license (“unlimited tracked hours”) and the older $50/user tiering, but the current published cloud tiers lead with storage + ingestion + inference.
What makes this different: most observability tools meter one thing. W&B meters four (seats, storage, traces, tokens) because it fused an MLOps tool, an LLM-observability tool, and an inference endpoint into one bill — so modeling your cost means modeling all four levers at once.
Pricing by product
| Plan | Price | Model seats | Storage | Weave ingestion | Key mechanics |
|---|---|---|---|---|---|
| Free | $0/mo | Up to 5 | 5 GB/mo | 1 GB/mo | Tracking, tracing, evals, registry, CI/CD; community support |
| Pro | Starts at $60/mo | Up to 10 | 100 GB/mo | 1.5 GB/mo | Unlimited teams, access controls, service accounts, priority support; +$0.03/GB storage, +$0.10/MB ingestion overage; $5/mo Inference credit |
| Enterprise | Custom | Customizable | Customizable | Customizable | Single-tenant, HIPAA, SSO, SCIM, audit logs, CMEK, private connectivity, dedicated solution engineer |
| Inference | Per token | — | — | — | 20+ open-weight models; ~$0.01–$2.75 per 1M input tokens; billed monthly in arrears; free credits (limited time) |
| Self-hosted (Personal) | $0/mo | 1 | — | — | Privately hosted; corporate use not allowed |
| Self-hosted (Advanced) | Custom | Customizable | Customizable | Customizable | Privately hosted Enterprise; free enterprise trial license option |
Pro is gated to “early-stage teams fewer than 50 employees” — exceed that and W&B requires a move to Enterprise. Academic research is free forever (all Pro features, unlimited tracked hours, 200 GB storage, 25 GB/mo Weave ingestion, up to 100 seats).
Sales motions across products: self-serve credit-card checkout (Free/Pro), product-led growth via the free wandb SDK, and sales-led (Enterprise custom quotes, annual invoicing, single-tenant/private hosting).
W&B Serverless Inference per-token examples (per 1M tokens): NVIDIA Nemotron 3 Ultra $0.75 in / $0.15 cached / $2.75 out; GPT-OSS 20B $0.05 in / $0.20 out; Qwen3 235B $0.10 in / $0.10 out; DeepSeek V4-Flash $0.01 in / $0.01 out.
Hidden costs : What Weights & Biases users actually pay
The $60 Pro fee is rarely the real bill — the three meters are. The single biggest surprise is Weave data ingestion overage at $0.10/MB. That works out to roughly $100 per GB, and an LLM app that logs verbose traces, large prompts, and eval results can produce several GB a month without anyone noticing — so a team that budgeted “$60 for W&B” can see a four-figure ingestion line.
For a Pro team running real GenAI workloads, the math is roughly:
| Line item | Monthly cost |
|---|---|
| Pro base plan | $60 |
| Included storage (first 100 GB) | $0 |
| Storage overage: 200 GB @ $0.03/GB | ~$6 |
| Included Weave ingestion (first 1.5 GB) | $0 |
| Weave ingestion overage: 5 GB @ $0.10/MB | ~$500 |
| Inference (per token, net of $5 credit) | varies |
| Estimated total (excl. inference) | ~$566 |
Other line items to watch: the 50-employee gate means growing teams are pushed off self-serve Pro into custom Enterprise quotes; HIPAA, SSO, audit logs, and BYO-bucket are Enterprise-only, so any regulated use jumps straight to a sales contract; and Inference is a separate per-token meter layered on top of everything — the $5/mo Pro credit barely dents real usage. CoreWeave Sandboxes also carry only a limited-time credit ($10 Free / $25 Pro) before becoming a paid add-on.
Want to estimate your own W&B bill? Use the Weights & Biases pricing calculator to model costs based on usage patterns. For broader context on metered observability spend, see the LLMOps cost-tracking gaps teams hit.
Pricing evolution : Weights & Biases pricing history and changes
Cadence
| Period | Price changes | Product / SKU additions | Notes |
|---|---|---|---|
| 2018 | Launch | wandb tracking SDK | Free SDK + team/enterprise seats; “compute hours” meter |
| 2022 | Refinement | ”tracked hours” rename | ~$50/user/mo Starter tiered by cumulative tracked hours; $1/hr overage |
| 2024 | New meter | W&B Weave | LLM observability adds a Weave-ingestion (GB) meter distinct from tracked hours |
| 2025 Q2 | Ownership | CoreWeave acquisition | ~$1.7B deal closes May 5, 2025; W&B folds into CoreWeave’s GPU cloud |
| 2026 | Restructure | Inference + Sandboxes | Free / Pro $60 / Enterprise; storage + ingestion + per-token Inference; CoreWeave Sandboxes |
Tracked range: 2018–present. Snapshot image attached for the 2026 capture; earlier tiers reconstructed from G2/ZenML teardowns and archived pricing pages.
Notable changes
- 2018 — Launched the
wandbSDK; free logging plus paid team/enterprise seats and a “compute hours” meter. - 2022 — Meter terminology shifted to “tracked hours”; Starter/Pro sold at ~$50/user/mo, tiered by cumulative tracked hours (to $100/$150), $1/hr overage, $0.03/GB storage.
- 2024 — W&B Weave shipped, introducing Weave data ingestion (GB) as a new value metric for GenAI observability.
- 2025-05-05 — CoreWeave completed its ~$1.7B acquisition, folding W&B into its GPU cloud with an interoperability pledge.
- 2026 — Tiers restructured to Free / Pro ($60/mo) / Enterprise, metered on storage ($0.03/GB), Weave ingestion ($0.10/MB), and per-token Serverless Inference, plus CoreWeave Sandboxes credits.
What’s unique : Weights & Biases’s distinctive pricing mechanics
1. Four meters under one bill. Seats, storage (GB), Weave ingestion (GB), and Inference (tokens) all bill independently. That reflects W&B’s history as three products (Models, Weave, Inference) stitched together — and it means buyers must forecast four distinct levers, not one usage number.
2. The asymmetric storage-vs-ingestion price. Model storage overage is a cheap $0.03/GB; Weave trace ingestion is $0.10/MB — roughly 3,000x more per byte. W&B prices the live observability stream (hot, queryable LLM traces) far above cold model artifacts, a deliberate signal of where the marginal cost and the value sit.
3. The 50-employee Pro tripwire. Pro is explicitly restricted to teams under 50 employees; outgrow it and you must move to Enterprise. It’s a rare case of a vendor coding its self-serve-to-sales handoff directly into the pricing page rather than relying on usage thresholds.
Strengths & weaknesses
| Strengths | Weaknesses |
|---|---|
| Transparent published Free/Pro tiers with explicit overage rates ($0.03/GB, $0.10/MB) | Four simultaneous meters make total cost hard to forecast |
| Genuinely free personal + free-forever academic (200 GB, unlimited tracked hours, 100 seats) | Weave ingestion at $0.10/MB (~$100/GB) can produce surprise four-figure bills |
| The MLOps category standard — 1M+ users, deep integrations, huge mind-share | HIPAA, SSO, audit logs, BYO-bucket all gated to custom Enterprise |
| End-to-end with CoreWeave GPU + Serverless Inference under one roof | 50-employee Pro cap forces growing teams into sales-quoted Enterprise |
Billing UX : Weights & Biases billing controls and transparency
- Billing controls — Pro is billed monthly or annually upfront; model seats are prorated when added mid-term, with no credit for removed seats. Weave ingestion, Inference, and storage are billed monthly in arrears on actual usage. Enterprise is invoiced annually upfront.
- Usage visibility — The platform surfaces storage and ingestion consumption against quota; the published pricing table and FAQ explain how each meter is calculated. Per-model Inference rates are listed on a dedicated inference page.
- Payment options — Self-serve credit-card checkout and a 30-day Pro free trial; Enterprise moves to annual invoicing with contract terms, single-tenant hosting, and security addenda (HIPAA BAA, CMEK).
Strategic wins : Why Weights & Biases’s pricing decisions worked
1. Free SDK as the category land-grab
The free wandb logging SDK embedded W&B into ML training workflows at OpenAI, Meta, and thousands of labs before any sales motion. Owning the developer’s first import wandb made W&B the default — distribution CoreWeave ultimately paid a reported ~$1.7B to acquire. See usage-based pricing fundamentals.
2. Free-forever academic seeding
Switching off the paid meter (tracked hours) entirely for academics — plus 200 GB and 100 seats — trains the next generation of ML practitioners on W&B, who then bring it into industry. It’s a long-cycle funnel disguised as generosity. Related: how AI companies structure pricing.
3. Pricing the hot stream above the cold store
Charging $0.10/MB for live Weave traces but $0.03/GB for model artifacts aligns price with the genuinely expensive thing (queryable, retained observability data). It’s a clean example of choosing the right usage metric per product surface rather than one blunt unit.
Areas to improve : Gaps in Weights & Biases’s pricing approach
1. Four-meter forecasting
Seats + storage + ingestion + tokens is a lot to model. Teams routinely undershoot the Weave ingestion line because $0.10/MB doesn’t read as expensive until it’s a multi-GB monthly bill. Better in-product forecasting would reduce bill shock.
2. Governance gated to Enterprise
SSO, HIPAA, audit logs, and BYO-bucket all require a custom Enterprise contract. A security-conscious 20-person team that needs SSO has no self-serve path — it jumps from $60 Pro straight to sales.
3. The 50-employee cliff
Coding a headcount cap into Pro is clean for W&B but abrupt for customers: a team that crosses 50 employees is forced into renegotiation regardless of actual usage, which can feel punitive mid-project.
Key takeaways
- A free SDK can be the whole moat. W&B’s
import wandbdefault drove the adoption that made it the MLOps standard — and the reported ~$1.7B CoreWeave exit. - Meter each product surface on its own value unit. Storage GB, Weave trace ingestion, and per-token Inference each price what that surface actually costs — but four meters demand strong forecasting UX.
- Price the hot stream above the cold store. $0.10/MB for live traces vs $0.03/GB for artifacts is a deliberate, defensible asymmetry.
- Free-for-academics is a multi-year funnel. Switching off the paid meter for research seeds the practitioners who later buy.
- Acquisition reshaped the bundle, not the philosophy. CoreWeave added Sandboxes and first-party Inference, but the freemium-plus-meters structure held.
UBP implications
- When you sell multiple products, meter each on its own unit — but invest in a unified forecasting view, or buyers will model the plan fee and miss the meters that dominate the bill.
- Differentiate hot vs cold data in your price. Live, queryable observability streams justify a far higher per-byte rate than cold artifact storage; charging one flat rate leaves money or trust on the table.
- A free, uncrippled developer entry point compounds. W&B’s free SDK and free-forever academic tier built the distribution that made the company acquirable — proof that the top of the funnel is a pricing decision, not just marketing.
Sources
- Weights & Biases pricing page (accessed 2026-06-16)
- W&B Serverless Inference pricing (accessed 2026-06-16)
- CoreWeave: completes acquisition of Weights & Biases (May 5, 2025) (accessed 2026-06-16)
- TechCrunch: CoreWeave acquires AI developer platform Weights & Biases (accessed 2026-06-16)
- ZenML: WandB pricing guide (accessed 2026-06-16)
- G2: Weights & Biases pricing (accessed 2026-06-16)
Bottom line
Weights & Biases prices like the multi-product platform it became: a free, sticky experiment-tracking SDK at the top, a $60/mo Pro tier for small teams, and custom Enterprise for everyone regulated or over 50 employees — all sitting on three usage meters (storage at $0.03/GB, Weave trace ingestion at $0.10/MB, and per-token Serverless Inference). The free personal and free-forever academic tiers are a deliberate land-grab that built the 1M-user distribution CoreWeave paid a reported ~$1.7 billion for in May 2025. The real friction is forecasting: the plan fee is the floor, and Weave ingestion overage is where unprepared GenAI teams get a four-figure surprise.
Want to compare Weights & Biases against other AI infrastructure companies? Browse the pricing blueprint.
Pricing timeline : Major events on a vertical axis
Each milestone below corresponds to a public pricing change, product launch, or material adjustment. Major events use a filled marker; minor adjustments use a faded one.
Restructured tiers: storage + ingestion + per-token Inference
Post-acquisition pricing settled on Free / Pro ($60/mo) / Enterprise, metered on storage ($0.03/GB overage), Weave ingestion ($0.10/MB overage), and per-token Serverless Inference, plus CoreWeave Sandboxes credits ($10/$25 per mo).
CoreWeave completes ~$1.7B acquisition
CoreWeave closed its acquisition of W&B for a reported ~$1.7 billion (W&B last valued at $1.25B in 2023), folding the developer platform into CoreWeave's GPU cloud while pledging continued interoperability across infra providers and models.
W&B Weave launches for LLM observability
W&B added Weave — tracing, evaluations, LLM-as-a-judge scorers, and production monitoring for GenAI apps — introducing a new value metric: Weave data ingestion (GB of logged traces), distinct from Models tracked hours.
'Compute hours' meter renamed to 'tracked hours'
W&B Models pricing shifted terminology from cumulative 'compute hours' to 'tracked hours'; the Starter/Pro tier was sold at roughly $50/user/mo, tiered by cumulative tracked hours (to $100/$150) with $1/hr overage and $0.03/GB storage.
Launched as wandb experiment tracking
Lukas Biewald and Chris Van Pelt founded W&B; the free experiment-tracking SDK (wandb) became the de-facto standard for logging ML training runs, monetized via team/enterprise seats and a 'compute hours' meter.
- · Weights & Biases is metered on three different value units at once: model storage (GB), W&B Weave data ingestion (GB of logged traces, overage at $0.10/MB), and per-token Serverless Inference — a legacy of stitching together an MLOps tool, an LLM-observability tool, and an inference endpoint under one bill.
- · CoreWeave bought W&B for a reported ~$1.7 billion, closing May 5, 2025 — roughly 1.4x the company's last private valuation of $1.25B (2023). The GPU cloud bought the developer mind-share that sits one layer above its hardware.
- · The W&B Pro tier has an unusual eligibility gate: it's only for 'early-stage teams fewer than 50 employees.' Outgrow that and W&B requires you to transition to Enterprise — a built-in self-serve-to-sales tripwire baked into the pricing page.
Questions & answers
- How much does Weights & Biases cost?
- W&B Free is $0/mo (5 model seats, 5 GB storage, 1 GB/mo Weave data ingestion). Pro starts at $60/month billed monthly (up to 10 seats, 100 GB storage, 1.5 GB/mo ingestion, priority support) and is meant for teams under 50 employees. Enterprise is custom-quoted and adds single-tenant hosting, HIPAA, SSO, audit logs, and customer-managed encryption.
- What does Weights & Biases meter on?
- Three things on top of the plan fee: storage (overage at $0.03/GB), W&B Weave data ingestion for LLM tracing/evals (overage at $0.10/MB above the included 1–1.5 GB/mo), and W&B Serverless Inference, which is billed per token. The legacy W&B Models meter was 'tracked hours' (compute hours of logged training), still reflected in the unlimited-tracked-hours academic license.
- How much does W&B Inference cost?
- W&B Serverless Inference is metered per token across 20+ open-weight models, billed monthly in arrears. Published rates range from about $0.01 per 1M input tokens (DeepSeek V4-Flash) up to $2.75 per 1M output tokens (NVIDIA Nemotron 3 Ultra), with GPT-OSS 20B at $0.05 input / $0.20 output and Qwen3 235B at $0.10 in / $0.10 out. Free credits are offered for a limited time; Pro includes a $5/mo Inference credit.
- Did the CoreWeave acquisition change W&B pricing?
- CoreWeave completed its ~$1.7B acquisition of Weights & Biases on May 5, 2025. The published tiers (Free / Pro $60 / Enterprise) were restructured around storage + Weave ingestion + per-token Inference, and CoreWeave Sandboxes (a $10/mo Free, $25/mo Pro credit) were added. CoreWeave committed to keeping the platform interoperable across any infrastructure provider and foundation model.