Best LLM API for Chatbots
Find the best LLM API for chatbots and conversational AI. Models ranked by human conversation preference (LMArena Elo), with verified pricing for dialogue, customer support, and interactive assistants.
MODELPRICEWATCH.COM · 2026-11-07
Cost calculator for this use casemonthly cost, top 3 models
- 1 Claude Opus 5.5
- $—
- 2 Claude Fable 5
- $—
- 3 Claude Fable 5.1
- $—
Full ranking — top 26 models
list prices, USD per 1M tokens| Model | LMArena Elo | Blended* | Input | Output | Context | Provider |
|---|---|---|---|---|---|---|
| 1Claude Opus 5.5 | 1505 Elo | $8.00 | $4.00 | $20.00 | 1M | Anthropic |
| 2Claude Fable 5 | 1504 Elo | $20.00 | $10.00 | $50.00 | 1M | Anthropic |
| 3Claude Fable 5.1 | 1504 Elo | $20.00 | $10.00 | $50.00 | 1M | Anthropic |
| 4Claude Opus 4.6 | 1503 Elo | $10.00 | $5.00 | $25.00 | 1M | Anthropic |
| 5Claude Opus 4.7 | 1501 Elo | $10.00 | $5.00 | $25.00 | 1M | Anthropic |
| 6Gemini 3.8 Flash | 1498 Elo | $1.50 | $0.750 | $3.75 | 1M | |
| 7Muse Spark 1.3 | 1496 Elo | $2.00 | $1.25 | $4.25 | 1M | Meta |
| 8Muse Spark 1.2 | 1493 Elo | $2.00 | $1.25 | $4.25 | 1M | Meta |
| 9Claude Opus 5 | 1490 Elo | $10.00 | $5.00 | $25.00 | 1M | Anthropic |
| 10Muse Spark 1.1 | 1490 Elo | $2.00 | $1.25 | $4.25 | 1M | Meta |
| 11Kimi K3 | 1488 Elo | $6.00 | $3.00 | $15.00 | 1M | Moonshot |
| 12Gemini 3.1 Pro | 1487 Elo | $4.50 | $2.00 | $12.00 | 2M | |
| 13GPT-5.6 Sol | 1485 Elo | $8.00 | $4.00 | $20.00 | 1M | OpenAI |
| 14Qwen3.8-Max | 1483 Elo | $3.00 | $2.00 | $6.00 | 1M | Alibaba |
| 15GPT-6.1 Sol | 1483 Elo | $4.00 | $2.00 | $10.00 | 1M | OpenAI |
| 16Gemini 3.6 Flash | 1483 Elo | $1.50 | $0.750 | $3.75 | 1M | |
| 17GLM-5.3 | 1482 Elo | $2.15 | $1.40 | $4.40 | 1M | Z.AI |
| 18Claude Opus 4.8 | 1482 Elo | $10.00 | $5.00 | $25.00 | 1M | Anthropic |
| 19GPT-5.5 | 1477 Elo | $11.25 | $5.00 | $30.00 | 1M | OpenAI |
| 20GLM-5.2 | 1475 Elo | $2.15 | $1.40 | $4.40 | 1M | Z.AI |
| 21Claude Sonnet 5.5 | 1473 Elo | $4.00 | $2.00 | $10.00 | 1M | Anthropic |
| 22Hy4 | — | $0.625 | $0.417 | $1.25 | 1M | Tencent |
| 23GPT-6.1 Terra | — | $2.00 | $1.00 | $5.00 | 1M | OpenAI |
| 24Kimi K3.1 Pro | — | $4.00 | $2.00 | $10.00 | 1M | Moonshot |
| 25GLM-5.3-Prime | — | $4.30 | $2.80 | $8.80 | 1M | Alibaba |
| 26Kimi K3.1 Pro HighSpeed | — | $8.00 | $4.00 | $20.00 | 1M | Moonshot |
Recent price movement in this ranking
price-only deltas · logged by the daily scan2 of the top 26 chatbot models have re-priced since we began tracking · last checked .
| Model | Changes | Latest move | Provider |
|---|---|---|---|
| GPT-5.6 Sol | 1 | price cut on : $5.00/$30.00 → $4.00/$20.00 /Mtok | OpenAI |
| Gemini 3.6 Flash | 1 | price cut on : $1.50/$7.50 → $0.750/$3.75 /Mtok |
Most recently, GPT-5.6 Sol cut its price on — a sign pricing in this category is still moving, so re-check before committing to a long-term choice. See all recent price moves →
How models are selected
Generally-available conversational models (mid-tier, flagship and fast classes), ranked by LMArena Elo — blind human preference votes on real conversations, independently collected. One row per model — host duplicates are collapsed. Models without an Elo rating rank below rated ones, cheapest first.
Prices are per million tokens (Mtok), sourced directly from — and linked to — official provider pricing pages. "Blended cost" is (3×input + 1×output) ÷ 4 — weighted toward input because real workloads read far more tokens than they generate.