Aug 15, 2025
Compare AI Text Models (2025)
By Core API Team
TextLLMComparison2025
Compare AI Text Models (2025)
Selecting an LLM involves trade‑offs in quality, latency, cost, tools, and safety. This guide contrasts popular models and shows how to integrate them via a unified API.
At‑a‑glance
| Model | Strengths | Trade‑offs | Best for | 
|---|---|---|---|
| GPT‑4o/4.1 | Reasoning, tools, broad ecosystem | Premium pricing | Assistants, agents, function‑calling | 
| Claude 3.5 Sonnet | Long context, helpful writing | Tooling still evolving | Research, drafting, knowledge tasks | 
| Gemini 1.5 Pro | Long context, multimodal | Output control varies | Multimodal RAG, document chat | 
| Llama 3.1 70B | Open weights, local control | Requires infra/ops | On‑prem, customization, privacy | 
Feature comparison
| Capability | GPT‑4o/4.1 | Claude 3.5 | Gemini 1.5 | Llama 3.1 | 
|---|---|---|---|---|
| JSON Mode | ✅ | ✅ | ✅ | ✅ (with prompts/tools) | 
| Function‑calling / Tools | ✅ | ✅ | ✅ | ✅ (framework‑dependent) | 
| Long Context | ✅ | ✅ | ✅ | ⚠️ (variant‑dependent) | 
| Vision | ✅ | ✅ | ✅ | ⚠️ (add‑ons) | 
| Streaming | ✅ | ✅ | ✅ | ✅ | 
Unified API examples
OpenAI Chat Completions — JavaScript
import axios from "axios";
const payload = {
  model: "gpt-4o-mini",
  messages: [
    { role: "system", content: "You are a concise assistant." },
    { role: "user", content: "Summarize the key benefits of a unified API layer." },
  ],
  temperature: 0.7,
};
const res = await axios.post(
  "https://api.coreapi.com/v1/openai/chat/completions",
  payload,
  { headers: { Authorization: `Bearer ${process.env.CORE_API_KEY}` } }
);
console.log(res.data);
Anthropic Messages — Python
import requests, os
payload = {
    "model": "claude-3-5-sonnet",
    "max_tokens": 512,
    "temperature": 0.7,
    "messages": [
        {"role": "user", "content": "List 5 common pitfalls in multi-vendor AI integrations."}
    ],
}
r = requests.post(
    "https://api.coreapi.com/v1/claude/messages",
    json=payload,
    headers={"Authorization": f"Bearer {os.environ['CORE_API_KEY']}"},
)
print(r.json())
Choosing a model
- Prefer GPT‑4o for robust tools/function‑calling and strong reasoning.
 - Prefer Claude for extended context and helpful writing.
 - Prefer Gemini for multimodal, long‑context document workflows.
 - Prefer Llama when you need open weights and deployment control.