🟩 Truly Free / Permanent Free Tier (No Credit Card Required)

✅ Groq — Fully free, high‑speed inference; no CC. https://console.groq.com/keys
✅ Google Gemini (AI Studio) — Permanent free tier; no CC. https://aistudio.google.com/app/apikey
✅ Mistral — ~1B tokens/month free; phone verification only. https://console.mistral.ai/api-keys
✅ Hugging Face Inference API — Free access to many serverless models; no CC. https://huggingface.co/login?next=%2Fsettings%2Ftokens
✅ NVIDIA NIM — 91 free endpoints for developers; no CC (developer program). https://build.nvidia.com/api-keys
✅ Cerebras — 1M tokens/day free; no CC. https://inference.cerebras.ai/api-keys
✅ Cloudflare Workers AI — Free neurons/day; no CC. https://dash.cloudflare.com
✅ GitHub Models — GPT‑4o, Grok‑3, etc., with free daily limits; no CC. https://github.com/settings/tokens
✅ OpenRouter — Several free models; no CC required. https://openrouter.ai/keys
✅ DeepSeek — Free tokens + extremely cheap usage; no CC required. https://platform.deepseek.com/api-keys
✅ SambaNova — Free credits + free tier; no CC. https://cloud.sambanova.ai/api-keys
✅ Cohere — 1,000 calls/month free; no CC. https://dashboard.cohere.com/api-keys
✅ Z.AI offers some free API models, such as GLM-4.7-Flash, GLM-4.5-Flash, and some free vision variants. These are intended for development and are subject to rate limits. https://open.bigmodel.cn/usercenter/apikeys
✅ OpenRouter Δεν ζητάει κάρτα , Δεν ζητάει recharge , Έχει πραγματικά δωρεάν μοντέλα (Qwen, LLaMA, Gemma, Mistral, DeepSeek) ,Δίνει API key χωρίς billing
✅ Cohere Δεν ζητάει κάρτα , Δεν ζητάει trial , Δεν ζητάει recharge , Το free tier ανανεώνεται κάθε μήνα (1.000 calls) Είναι πραγματικό free API usage

🟨 Free Credits (Not Permanent Free Tier)

(Still free, but requires signup credits or limited trial)

Fireworks AI — ~$1 free credit; CC not required for initial use. https://fireworks.ai/console/api-keys
xAI (Grok) — $25 signup credits; CC not required initially. https://console.x.ai/api-keys
AI21 Labs — Free trial credits; CC not required until trial ends. https://studio.ai21.com/account/api-key

🟥 No Free Tier (Credit Card Required)

OpenAI — Free tier effectively unusable; $5 deposit required.
Anthropic — No permanent free tier; trial credits require billing.
Together AI — No free tier; $5 minimum deposit.
Replicate — Requires credit card for running models. (No direct citation found; inferred from provider policy)
Moonshot AI — Requires manual recharge; no free tier. (Inference based on market patterns)
Z.ai / GLM 5.2 — Typically gated behind paid access or platform shells. (Inference)
Alibaba Qwen — Often requires domestic phone verification or billing. (Inference)