GPT-3.5 Turbo 16k
Fast and lightToolsOpenAI · Released August 2023 · Knowledge cutoff September 2021
This model offers four times the context length of gpt-3.5-turbo, allowing it to support approximately 20 pages of text in a single request at a higher cost. Training data: up...
It is part of OpenAI's GPT family, where Sol, Luna and Terra mark the current generation's capability tiers and Pro servings trade speed for deeper computation.
Facts and pricing
- Provider
- OpenAI
- Context window
- 16K tokens
- Input price
- 33.0 credits / 1M tokens ($3.00 raw)
- Output price
- 44.0 credits / 1M tokens ($4.00 raw)
- Vision (image input)
- No
- Tool calling
- Yes
- Extended reasoning
- No
Credits are what Zeplik bills: 1 credit = $0.10, computed from the raw provider rate with a 1.10x margin. Raw prices shown per 1M tokens.
Try GPT-3.5 Turbo 16k now
What GPT-3.5 Turbo 16k is best for
- High-volume everyday tasks where speed and cost matter: summaries, drafts, quick questions
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Example prompts
Prompts that suit a fast and light model like GPT-3.5 Turbo 16k:
- Summarize this article in five bullet points
- Rewrite this email to be shorter and friendlier
- Give me ten name ideas for a hiking newsletter
- Translate this paragraph to Spanish and keep the tone
OpenAI family
| Model | Context | Input cr/M | Output cr/M | Released |
|---|---|---|---|---|
| GPT-5.6 Luna Pro | 1.1M | 11.0 | 66.0 | July 2026 |
| GPT-5.6 Luna | 1.1M | 11.0 | 66.0 | July 2026 |
| GPT-5.6 Terra Pro | 1.1M | 27.5 | 165 | July 2026 |
| GPT-5.6 Terra | 1.1M | 27.5 | 165 | July 2026 |
| GPT-5.6 Sol Pro | 1.1M | 55.0 | 330 | July 2026 |
| GPT-5.6 Sol | 1.1M | 55.0 | 330 | July 2026 |
| GPT Chat Latest | 400K | 55.0 | 330 | May 2026 |
| GPT-5.5 Pro | 1.1M | 330 | 1980 | April 2026 |
| GPT-5.5 | 1.1M | 55.0 | 330 | April 2026 |
| GPT-5.4 Image 2 | 272K | 88.0 | 165 | April 2026 |
Frequently asked questions
- What is GPT-3.5 Turbo 16k?
- GPT-3.5 Turbo 16k is an AI model by OpenAI. This model offers four times the context length of gpt-3.5-turbo, allowing it to support approximately 20 pages of text in a single request at a higher cost. Training data: up...
- How much does GPT-3.5 Turbo 16k cost on Zeplik?
- Input tokens cost 33.0 credits per million and output tokens 44.0 credits per million (1 credit = $0.10; the raw provider rates are $3.00 and $4.00 per million). New accounts start with free credits.
- How long can a conversation with GPT-3.5 Turbo 16k be?
- GPT-3.5 Turbo 16k has a 16K-token context window (16,385 tokens), which covers the conversation plus any documents you attach.
- Does GPT-3.5 Turbo 16k support images and tools?
- GPT-3.5 Turbo 16k is text-only and supports tool calling.
Related models
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...
GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...
GPT-5.6 Sol Pro is the same underlying model as [GPT-5.6 Sol](https://openrouter.ai/openai/gpt-5.6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks...