Fireworks AI vs Weights & Biases

Fireworks AI — Infrastructure · Private · $17.5B valuation · 4 of 4 figures sourced  |  Weights & Biases — Infrastructure · Acquired · 1 of 1 figure sourced

Relationship

Fireworks Inference and W&B Serverless Inference do comparable work on model hosting; both also serve buyers who need to serve a model in production; Weights & Biases is acquired, with no independent scale.

Assembled from the recorded fields for this pair, not hand-checked. The comparison below is read from each company’s own profile.

3 of 5 capabilitiesShared product type

3 of 5 capabilities — Shares model hosting, model inference and model training.

Ludbee capability tags · from the product records

Shared product type — Both ship API service.

Ludbee product records

Aligned comparison

FieldFireworks AIWeights & Biases
Size$17.5B valuationnot disclosed
Employees115—
Founded20222017 5 yrs earlier
StatusPrivateAcquired
CategoryInfrastructureInfrastructure match
Stack layerAPI service, Model APIAPI service, Developer tool, Platform
HeadquartersSan Mateo, USASan Francisco, USA

Capability overlap

Shared · 3

Model hostingModel inferenceModel training

Not verified for Weights & Biases · 2

Agent orchestrationSpeech to text

Recorded for Fireworks AI. Weights & Biases’s product records say nothing either way — a missing record is not a missing capability.

Not verified for Fireworks AI · 2

Evaluation and observabilityGPU cloud

Recorded for Weights & Biases. Fireworks AI’s product records say nothing either way — a missing record is not a missing capability.

Products, side by side

Algorithmic pairing — assembled from recorded fields, not hand-checked

Fireworks AI

API service

Fireworks InferenceAPI service

Serving for frontier open models and for a customer's own post-trained versions of them, on an inference engine tuned at each layer.

Fireworks Speech RecognitionAPI service

Real-time and batch speech-to-text on Fireworks, aimed at voice workflows that need low-latency transcription at scale.

Fireworks TrainingAPI service

Training and retraining of custom models on Fireworks, offered across several training surfaces and served on the same platform.

Weights & Biases

API service

W&B Serverless InferenceAPI service

Hosted inference service for open-source and commercial LLMs (OpenAI, Qwen, Llama, Kimi, Phi, DeepSeek, Z.AI) without managing infrastructure.

No counterpart

Fireworks AI sells these in a stack layer with no product recorded for Weights & Biases yet — nothing on the other side to compare them against.

Model API

Fireworks AIModel API

Hosted API for serving and fine-tuning open-weight models, billed per token.

Fireworks NexusModel API

Drop-in API endpoint that routes each request across models to trade cost against quality.

Weights & Biases sells these in a stack layer with no product recorded for Fireworks AI yet — nothing on the other side to compare them against.

Developer tool

W&B WeaveDeveloper tool

Tracing, evaluation and production monitoring for LLM and agent applications, capturing each call so prompts and outputs can be scored over time.

Platform

W&B ModelsPlatform

Experiment tracking for model training runs, recording hyperparameters, metrics and artifacts so runs can be compared, swept and reproduced.

W&B RegistryPlatform

Curated central repository providing versioning, aliases, lineage tracking and governance for models and datasets across the ML lifecycle.

W&B Serverless RLPlatform

Managed reinforcement-learning fine-tuning service for LLMs on CoreWeave's managed GPU cluster, billed per-token for rollouts with automatic scale-to-zero.

W&B Serverless SFTPlatform

Serverless supervised fine-tuning for LLMs on CoreWeave's managed GPU cluster, run alongside Serverless RL in a unified workflow via the Agent Reinforcement Trainer (ART) API.