OpenAI vs Fireworks AI
A comparison of OpenAI and Fireworks AI built from values read directly from each provider's own documentation, with the source recorded against every figure.
The short answer
- Pick OpenAI if
- Work that fits inside the short-context rate, where the cheapest tier is $0.20 per million input tokens and the batch tier halves everything above it.
- Pick Fireworks AI if
- Running open-weight models without operating GPUs — the same DeepSeek and Qwen checkpoints the labs publish, served per token, with a path to dedicated hardware if throughput demands it.
6 sourced criteria separate them:
- Pricing model
- OpenAI: Per million tokens, with a second rate above the short-context threshold — long-context input and output cost roughly double. Batch, Flex, Fast and standard tiers are priced separately, and regional processing adds a 10% uplift on models released from March 2026.
- Fireworks AI: Three products on one bill. Serverless inference is per token, per model. Fine-tuning is per million TRAINING tokens by parameter band — $0.50 for models up to 16B, $10.00 above 300B. Dedicated GPUs are hourly: $7.00 for an H100 or H200, $10.00 for a B200.
- Input price, top model
- OpenAI: $10 per million input tokens for gpt-6-astra at short context, rising to $20 above the short-context threshold. gpt-5.6-sol is $4 and gpt-5.6-terra $2.
- Fireworks AI: $3.00 per million input tokens for Kimi K3, the most expensive model in its serverless catalogue. Fireworks hosts other labs' open-weight models rather than its own, so "flagship" here means the top of what it serves.
- Output price, top model
- OpenAI: $50 per million output tokens for gpt-6-astra at short context, $75 at long context.
- Fireworks AI: $15.00 per million output tokens for Kimi K3.
- Input price, cheapest model
- OpenAI: $0.20 per million input tokens for gpt-5.6-luna at short context, with output at $1.20.
- Fireworks AI: $0.15 per million input tokens for GLM 5.3 Flash, with output at $0.50. DeepSeek-V4-Flash is $0.22 in and $0.66 out — the same model DeepSeek itself sells at $0.44 peak.
- Context window
- OpenAI: 1,050,000 tokens on gpt-6-astra, of which at most 922,000 may be input.
- Fireworks AI: 1,048,576 tokens on Kimi K3, GLM 5.3 and both DeepSeek V4 variants; 262,144 on Qwen3.8 and 131,072 on Muse Glimmer 30B. The window is the model's, not Fireworks'.
- Max output tokens
- OpenAI: 128,000 tokens on gpt-6-astra.
- Fireworks AI: No separate output cap. max_tokens is bounded by the model's context length — prompt plus completion must fit inside it — and what happens on overflow is set by context_length_exceeded_behavior rather than a fixed ceiling.
Pick the criteria you care about. The chart counts how many of them lean toward each provider — the same read as scanning the bars below, just totalled for the ones you chose.
OpenAI 0
Fireworks AI 0
At a glance.
| Criterion | OpenAI | Fireworks AI |
|---|---|---|
| Pricing | ||
| Pricing model | Per million tokens, with a second rate above the short-context threshold — long-context input and output cost roughly double. Batch, Flex, Fast and standard tiers are priced separately, and regional processing adds a 10% uplift on models released from March 2026. | Three products on one bill. Serverless inference is per token, per model. Fine-tuning is per million TRAINING tokens by parameter band — $0.50 for models up to 16B, $10.00 above 300B. Dedicated GPUs are hourly: $7.00 for an H100 or H200, $10.00 for a B200. |
| Inference | ||
| Input price, top model | $10 per million input tokens for gpt-6-astra at short context, rising to $20 above the short-context threshold. gpt-5.6-sol is $4 and gpt-5.6-terra $2. | $3.00 per million input tokens for Kimi K3, the most expensive model in its serverless catalogue. Fireworks hosts other labs' open-weight models rather than its own, so "flagship" here means the top of what it serves. |
| Output price, top model | $50 per million output tokens for gpt-6-astra at short context, $75 at long context. | $15.00 per million output tokens for Kimi K3. |
| Input price, cheapest model | $0.20 per million input tokens for gpt-5.6-luna at short context, with output at $1.20. | $0.15 per million input tokens for GLM 5.3 Flash, with output at $0.50. DeepSeek-V4-Flash is $0.22 in and $0.66 out — the same model DeepSeek itself sells at $0.44 peak. |
| Context window | 1,050,000 tokens on gpt-6-astra, of which at most 922,000 may be input. | 1,048,576 tokens on Kimi K3, GLM 5.3 and both DeepSeek V4 variants; 262,144 on Qwen3.8 and 131,072 on Muse Glimmer 30B. The window is the model's, not Fireworks'. |
| Max output tokens | 128,000 tokens on gpt-6-astra. | No separate output cap. max_tokens is bounded by the model's context length — prompt plus completion must fit inside it — and what happens on overflow is set by context_length_exceeded_behavior rather than a fixed ceiling. |
| Prompt caching | Supported | Supported |
Where they differ.
Pricing model
- OpenAI
- Per million tokens, with a second rate above the short-context threshold — long-context input and output cost roughly double. Batch, Flex, Fast and standard tiers are priced separately, and regional processing adds a 10% uplift on models released from March 2026.
- Fireworks AI
- Three products on one bill. Serverless inference is per token, per model. Fine-tuning is per million TRAINING tokens by parameter band — $0.50 for models up to 16B, $10.00 above 300B. Dedicated GPUs are hourly: $7.00 for an H100 or H200, $10.00 for a B200.
Sources (2) →Sources ↓
- Pricing — OpenAI API docs ↗
“Prices per 1M tokens. [...] Regional processing (data residency) endpoints are charged a 10% uplift for models released on or after March 5, 2026 [...] Priority processing was renamed Fast mode on July 30, 2026.”
Read 2026-09-06 · official pricing
- Pricing — Fireworks AI ↗
“MODELS UP TO 16B PARAMETERS $0.50 $1.00 $1.00 $2.00 [...] MODELS >300B (E.G. DEEPSEEK V3, KIMI K2) $10.00 $20.00 $20.00 $40.00 [...] H100 80 GB GPU $7.00 $8.00 H200 141 GB GPU $7.00 $8.00 B200 180 GB GPU $10.00 $13.00”
Read 2026-09-06 · official pricing
Input price, top model
- OpenAI
- $10 per million input tokens for gpt-6-astra at short context, rising to $20 above the short-context threshold. gpt-5.6-sol is $4 and gpt-5.6-terra $2.
- Fireworks AI
- $3.00 per million input tokens for Kimi K3, the most expensive model in its serverless catalogue. Fireworks hosts other labs' open-weight models rather than its own, so "flagship" here means the top of what it serves.
Sources (2) →Sources ↓
- Pricing — OpenAI API docs ↗
“| gpt-6-astra | $10.00 | $1.00 | $12.50 | $50.00 | $20.00 | $2.00 | $25.00 | $75.00 | [...] | gpt-5.6-sol | $4.00 [...] | gpt-5.6-terra | $2.00”
Read 2026-09-06 · official pricing
- Models — Fireworks AI ↗
“Kimi K3 $3/M Input • $15/M Output • 1048576 Context”
Read 2026-09-06 · official pricing
Output price, top model
- OpenAI
- $50 per million output tokens for gpt-6-astra at short context, $75 at long context.
- Fireworks AI
- $15.00 per million output tokens for Kimi K3.
Sources (2) →Sources ↓
- Pricing — OpenAI API docs ↗
“| gpt-6-astra | $10.00 | $1.00 | $12.50 | $50.00 | $20.00 | $2.00 | $25.00 | $75.00 |”
Read 2026-09-06 · official pricing
- Models — Fireworks AI ↗
“Kimi K3 $3/M Input • $15/M Output • 1048576 Context”
Read 2026-09-06 · official pricing
Input price, cheapest model
- OpenAI
- $0.20 per million input tokens for gpt-5.6-luna at short context, with output at $1.20.
- Fireworks AI
- $0.15 per million input tokens for GLM 5.3 Flash, with output at $0.50. DeepSeek-V4-Flash is $0.22 in and $0.66 out — the same model DeepSeek itself sells at $0.44 peak.
Sources (2) →Sources ↓
- Pricing — OpenAI API docs ↗
“| gpt-5.6-luna | $0.20 | $0.02 | $0.25 | $1.20 | $0.40 | $0.04 | $0.50 | $1.80 |”
Read 2026-09-06 · official pricing
- Models — Fireworks AI ↗
“GLM 5.3 Flash $0.15/M Input • $0.5/M Output • 1048576 Context [...] DeepSeek-V4-Flash-0731 $0.22/M Input • $0.66/M Output • 1048576 Context”
Read 2026-09-06 · official pricing
Context window
1,050,000 tokens on gpt-6-astra, of which at most 922,000 may be input.
1,048,576 tokens on Kimi K3, GLM 5.3 and both DeepSeek V4 variants; 262,144 on Qwen3.8 and 131,072 on Muse Glimmer 30B. The window is the model's, not Fireworks'.
Sources (2) →Sources ↓
- gpt-6-astra — OpenAI API docs ↗
“- 1,050,000 context window - Maximum input tokens: 922,000”
Read 2026-09-06 · official docs
- Models — Fireworks AI ↗
“Kimi K3 $3/M Input • $15/M Output • 1048576 Context [...] Qwen3.8-2.4T-A95B $2/M Input • $6/M Output • 262144 Context [...] Muse Glimmer 30B $0.35/M Input • $1.5/M Output • 131072 Context”
Read 2026-09-06 · official pricing
Max output tokens
- OpenAI
- 128,000 tokens on gpt-6-astra.
- Fireworks AI
- No separate output cap. max_tokens is bounded by the model's context length — prompt plus completion must fit inside it — and what happens on overflow is set by context_length_exceeded_behavior rather than a fixed ceiling.
Sources (2) →Sources ↓
- gpt-6-astra — OpenAI API docs ↗
“- 128,000 max output tokens”
Read 2026-09-06 · official docs
- Chat Completions API — Fireworks docs ↗
“The maximum number of tokens to generate in the completion. If the token count of your prompt plus max_tokens exceeds the model's context length, the behavior depends on context_length_exceeded_behavior.”
Read 2026-09-07 · official docs
When these numbers change, hear about it. Sources are re-checked monthly; a repricing goes out as a short note.
Which should you choose?
Choose OpenAI if…
Work that fits inside the short-context rate, where the cheapest tier is $0.20 per million input tokens and the batch tier halves everything above it.
Editorial · Palash Bagchi · approved
Choose Fireworks AI if…
Running open-weight models without operating GPUs — the same DeepSeek and Qwen checkpoints the labs publish, served per token, with a path to dedicated hardware if throughput demands it.
Editorial · Palash Bagchi · approved
Consider something else if…
- OpenAI: Long prompts cross into the long-context rate and roughly double the bill, which is a cliff the flat-rate vendors do not have.
- Fireworks AI: You want a frontier proprietary model: Fireworks serves other people's open weights, so the ceiling is whatever the open ecosystem has released.
Documented by only one.
These criteria are published by one provider and not the other. An absence here means we have not found a source, not that the feature is missing.
Questions this comparison answers.
Should I choose OpenAI or Fireworks AI?
Pick OpenAI if Work that fits inside the short-context rate, where the cheapest tier is $0.20 per million input tokens and the batch tier halves everything above it.
Pick Fireworks AI if Running open-weight models without operating GPUs — the same DeepSeek and Qwen checkpoints the labs publish, served per token, with a path to dedicated hardware if throughput demands it.