vs
Fireworks AI vs xAI
A closed lab with live X data against an open-model host. xAI sells Grok; Fireworks sells speed and fine-tuning on open weights like DeepSeek and Kimi.
By The Subconscious Team · Updated
Fireworks AI vs xAI: key differences
xAI and Fireworks answer different questions. xAI is a closed lab selling its own Grok models: Grok 4.6 as the flagship at $2 in and $6 out with a 500K window, and older Grok 4.20 and 4.3 at $1.25 in and $2.50 out with 1M context. Its hook is native Web Search and X Search, which pull live posts from X in a way no other lab offers. Fireworks sells none of its own models. It hosts 400+ open ones, including DeepSeek V4 Pro and Kimi K3, and competes on serving speed, posting 167 to 174 tokens per second on DeepSeek V4 Pro in third-party tests.
Long prompts expose a pricing difference. Once a prompt passes 200K tokens, xAI bills the whole request at double, while Fireworks offers DeepSeek V4 Pro at its full 1M context. Control is the other axis. Grok weights are closed, so there is nothing to fine-tune. Fireworks runs SFT, DPO and RL and serves tuned models at base price, with SOC 2, HIPAA, ISO and cloud marketplace billing. xAI lists fewer cloud-marketplace options than the largest labs. It still wins for news, market and social agents that need fresh data.
What Fireworks AI and xAI do
Fireworks AI
Fireworks AI was founded in 2022 by former Meta PyTorch engineers led by CEO Lin Qiao, and it sells speed on open models. Its custom serving stack has posted 167 to 174 tokens per second on DeepSeek V4 Pro in third-party measurements, several times what most GPU peers hit on the same model. The catalog holds 400+ models across text, vision, audio and embeddings, served through an OpenAI-compatible API. In July 2026 it raised a $1.505B Series D at a $17.5B valuation, with a reported $1B+ run rate and 40T+ tokens a day.
Example models: DeepSeek V4 Pro, Kimi K3
Full Fireworks AI profilexAI
xAI sells the Grok models through its own API. Grok 4.6 is the current flagship and xAI tells developers to use it for everything outside audio, image and video, code included. It has a 500K context window and costs $2 in and $6 out per million tokens under 200K prompt tokens. Older Grok 4.20 and 4.3 models keep a 1M window at $1.25 in and $2.50 out, which is aggressive for that capability class.
Example models: Grok 4.6, Grok 4.20
Full xAI profileShould you choose Fireworks AI or xAI?
Fireworks AI
Choose Fireworks AI for
- Fine-tuning an open model for a narrow task
- Long prompts on DeepSeek V4 Pro at full 1M context
- Procurement through AWS or GCP marketplaces
xAI
Choose xAI for
- Social listening and news agents that need live X data
- Cheap output tokens on a closed reasoning model
- Teams that also want first-party image, video and audio APIs
Fireworks AI vs xAI at a glance
| Attribute | Fireworks AI | xAI |
|---|---|---|
| Model access | Open weights | Closed |
| Flagship models | DeepSeek V4 Pro, Kimi K3 | Grok 4.6, Grok 4.20, grok-build |
| Speed | 167–174 tok/s on DeepSeek V4 Pro | ~54 tok/s on Grok 4.6 |
| Price | Fine-tunes served at base price | $2 in, $6 out (Grok 4.6); 2x past 200K |
| Customization | SFT, DPO, RFT; Training API | Unknown |
| Deployment | Serverless, dedicated GPUs | First-party API |
| Long context | Full 1M on DeepSeek V4 Pro | 500K (4.6), 1M (4.20, 4.3) |
Frequently asked questions
What is the difference between Fireworks AI and xAI?
A closed lab with live X data against an open-model host. xAI sells Grok; Fireworks sells speed and fine-tuning on open weights like DeepSeek and Kimi.
When should I choose Fireworks AI over xAI?
Fine-tuning an open model for a narrow task; Long prompts on DeepSeek V4 Pro at full 1M context; Procurement through AWS or GCP marketplaces.
When should I choose xAI over Fireworks AI?
Social listening and news agents that need live X data; Cheap output tokens on a closed reasoning model; Teams that also want first-party image, video and audio APIs.
Is Fireworks AI or xAI cheaper?
Fireworks AI: Fine-tunes served at base price. xAI: $2 in, $6 out (Grok 4.6); 2x past 200K. The cheaper choice depends on the model and workload.
Which has more context, Fireworks AI or xAI?
Fireworks AI: Full 1M on DeepSeek V4 Pro. xAI: 500K (4.6), 1M (4.20, 4.3).
Related comparisons
Running long-horizon agents?
If your agents run past 200K tokens, compare both against Subconscious. Our inference stack treats a long-horizon trace as the primary workload, so speed, cost, and accuracy hold up deep into the trace.