Cheapest AI model for long documents
Top pick: DeepSeek V4.1 Flash (DeepSeek) at about $32.40/mo for an example 100M input + 2M output tokens per month. Needs tier ≥2 and a published context window ≥500,000 tokens; 5 of 25 models qualify. Prices last checked 2026-10-13.
Cheapest qualifying models, ranked
| # | Model | Provider | Input $/M | Output $/M | Context | Tier | Example $/mo | vs top pick |
|---|---|---|---|---|---|---|---|---|
| 1 | DeepSeek V4.1 Flash | DeepSeek | $0.3 | $1.2 | 1000000 | 2 | $32.40 | Top pick |
| 2 | Mistral Large 4 | Mistral | $0.68 | $2.09 | 1000000 | 3 | $72.18 | +$39.78/mo |
| 3 | Grok 4.3 | xAI | $1.25 | $2.5 | 1000000 | 2 | $130.00 | +$97.60/mo |
| 4 | DeepSeek V4 Pro | DeepSeek | $1.32 | $3.96 | 1000000 | 3 | $139.92 | +$107.52/mo |
| 5 | Grok 4.7 | xAI | $2.0 | $6.0 | 500000 | 3 | $212.00 | +$179.60/mo |
Caveat: Only models with a published context ≥500K are considered; several providers bill more above 200K–272K prompt tokens.
How the example bill is computed
We assume 100M input and 2M output tokens per month and multiply by each model's standard per-1M-token price. For the top pick, DeepSeek V4.1 Flash (DeepSeek): (100M × $0.3) + (2M × $1.2) = $32.40 per month (prices checked 2026-10-13).
Tiers 1–4 are our own rough capability judgment (1 = light, 4 = frontier), not a benchmark. This job needs tier ≥2 and a published context window ≥500,000 tokens, so only those models are ranked (5 of 25 qualify). Standard pay-as-you-go text prices only: no batch or cached-input discounts. Cost only, not quality; different tokenizers count the same text differently.
Related head-to-head comparisons
- Grok 4.7 vs GPT-6.1 Sol
- DeepSeek V4 Pro vs GPT-6.1 Sol
- Mistral Large 4 vs DeepSeek V4 Pro
- Gemini 3.8 Flash vs Grok 4.3
Other jobs: Simple Q&A / chat · Coding · Hard reasoning. See every model on the full price table or estimate your own bill with the savings calculator.