OpenAI API vs Together AI
Frontier models: GPT-5, o-series reasoning, image, audio, embeddings
vs. Open-source LLM infra — inference + fine-tuning + dedicated GPUs + image/video/audio
Pricing tiers
OpenAI API
Free Tier (Trial)
$5 free credit for new accounts. Rate-limited.
Free
Pay-as-you-go
No monthly min. Per-token pricing by model.
$0 base (usage-based)
Usage Tiers (1-5)
Automatic tier promotion based on cumulative spend. Higher tiers = higher rate limits + new model access.
$0 base (usage-based)
Enterprise
Custom. Priority access, SLA, dedicated capacity.
Custom
Together AI
Pay-as-you-go
Per-token pricing for serverless inference. No minimum.
$0 base (usage-based)
Dedicated Endpoints
Single-tenant GPU endpoints billed hourly.
$0 base (usage-based)
Batch API (50% off)
50% discount for async batch processing on most serverless models.
$0 base (usage-based)
Reserved GPU Clusters
6+ day commitments with discounted reserved rates.
$0 base (usage-based)
Enterprise
Custom. Private deployments, VPC, SLAs, dedicated support.
Custom
Free-tier quotas head-to-head
Comparing free-tier on OpenAI API vs payg on Together AI.
| Metric | OpenAI API | Together AI |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
OpenAI API · 12 features
- Assistants API — Stateful assistants with tools, threads, file search.
- Batch API — 50% discount for async processing within 24h.
- Chat Completions API — Classic /v1/chat/completions endpoint.
- Files API — Upload docs for retrieval, fine-tuning, batch.
- Fine-Tuning — Supervised + DPO fine-tuning for GPT-4o, GPT-4.1, GPT-4o-mini.
- Function Calling — JSON-schema tool calling; parallel calls supported.
- Moderation — Safety classifier API (free).
- Prompt Caching — Auto-cache repeated prefixes; 50% cheaper cached hits.
- Realtime API — WebSocket streaming voice + text with low latency.
- Responses API — Stateful conversational API.
- Structured Outputs — Enforced JSON schema compliance.
- Vision — Image input for GPT models.
Together AI · 14 features
- Audio (ASR + TTS) — Whisper Large v3 + Cartesia Sonic-3.
- Batch API — 50% discount for async processing.
- Code Interpreter — LLM with integrated code execution.
- Code Sandbox — Secure Python execution environment.
- Dedicated Endpoints — Single-tenant GPU endpoints for consistent latency.
- Embeddings — BGE + nomic + mxbai embedding models.
- Fine-Tuning — LoRA + full fine-tune + DPO on Llama, Qwen, Mistral.
- Image Generation — FLUX.2, SD3, Ideogram, etc.
- OpenAI-Compat API — Drop-in OpenAI SDK replacement.
- Private Deploy — Dedicated tenant + VPC.
- Reranker — Rerank model for RAG retrieval refinement.
- Reserved Clusters — Discounted GPU clusters for committed use.
- Serverless Inference — 200+ open models. OpenAI-compatible API.
- Video Generation — Veo 3.0, Kling 2.1, Vidu 2.0.
Developer interfaces
| Kind | OpenAI API | Together AI |
|---|---|---|
| CLI | — | Together CLI |
| SDK | openai-dotnet, openai-go, openai-node, openai-python | together-js, together-python |
| REST | OpenAI REST API | Code Sandbox / Interpreter, Dedicated Endpoints, Together REST API (OpenAI-compat) |
| MCP | OpenAI MCP | — |
| OTHER | Realtime API (WebSocket) | — |
Staxly is an independent catalog of developer platforms. Outbound links to OpenAI API and Together AI are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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