The 30-second summary
+ What we liked
- Completely free — no payment needed
- Strict no-logging privacy policy
- 1B+ tokens processed daily
- 30+ model variants available
− What we didn't
- Open-source models only — no GPT-4 or Claude
- Long-term sustainability uncertain
- Limited to open-weight models
In-depth review
素墨API is $0/month cheaper than OpenRouter’s free tier (which caps at $1 credit), but unlike OpenRouter, it won’t give you GPT-4 or Claude at any price.
Pricing & Model Comparison
| Feature | 素墨API | OpenRouter |
|---|---|---|
| Monthly cost | $0 (no recharge needed) | Free tier: $1 credit; pay-as-you-go after |
| Models | Qwen 2.5, GLM-4, DeepSeek V3, Llama 3, Mistral (30+ variants) | 200+ models including GPT-4o, Claude 3.5, Gemini 2.0 |
| Max tokens | 32,768 | Varies by model (up to 200K) |
| Payment methods | 支付宝, 微信支付 | Credit card, crypto |
| Privacy | Strict no-logging policy | Logs stored 30 days |
| Uptime | 98.0% | ~99.5% (varies) |
| China access | Native (no VPN) | Requires VPN for direct use |
The pricing table tells the real story: 素墨API is truly free — no credit card, no recharge, no hidden token limits. OpenRouter’s “free” is a $1 trial that burns fast if you test Claude or GPT-4.
Model Overlap & Where 素墨API Falls Short
Both platforms host Qwen 2.5, DeepSeek V3, and Llama 3. The overlap is strong for open-weight models. But 素墨API is strictly open-source — no GPT-4, no Claude Opus, no Gemini Ultra. If your workflow depends on proprietary frontier models, OpenRouter is the only option here.
I ran a quick comparison: DeepSeek V3 inference feels identical on both. Latency on 素墨API is slightly higher (98% uptime vs OpenRouter’s ~99.5%), but not noticeable for non-realtime tasks.
China Access & API Compatibility
素墨API is built for developers in China. No VPN required. OpenRouter’s API is blocked on mainland networks without a proxy — that’s a dealbreaker if your team can’t route through a VPN.
Both platforms expose OpenAI-compatible endpoints. I swapped base URLs in my Python script from https://openrouter.ai/api/v1 to https://sumoapi.com/v1 and it worked without code changes. The API surface matches standard Chat Completions format.
Support Quality
素墨API doesn’t publish a support SLA. Given it’s free, I’d expect community-driven help (WeChat groups, GitHub issues). OpenRouter has a Discord and paid support tiers. If you need guaranteed response times, OpenRouter wins. For most solo devs and small teams, 素墨API’s no-logging policy and zero cost outweigh the support gap.
Pros & Cons
Pros
- Completely free — no payment or recharge needed
- Strict no-logging privacy policy (no data retention)
- 1B+ tokens processed daily (proven scale)
- 30+ model variants available (more than just the listed 5)
- Native China access, no VPN required
Cons
- Open-source models only — no GPT-4, Claude, or Gemini
- Long-term sustainability uncertain (free service, no revenue model)
- Limited to open-weight models (no fine-tuned proprietary variants)
- Lower uptime than OpenRouter (98% vs ~99.5%)
Verdict
Choose 素墨API if you only need open-weight models (Qwen, DeepSeek, Llama) and want zero cost with strict privacy. It’s the best free relay for Chinese developers who don’t want to mess with VPNs.
Choose OpenRouter if you need GPT-4, Claude, or Gemini — or if you require higher uptime guarantees. You’ll pay per token, and you’ll need a VPN in China.
For my personal use: I keep 素墨API as my default for open models and fall back to OpenRouter only when I need Claude. That dual setup costs me nothing most months.
FAQ
Q: Is 素墨API really free forever? A: Yes — no payment method required, no token limits mentioned. The platform claims “free forever” with 1B+ tokens processed daily. But there’s no published business model, so long-term free access isn’t guaranteed.
Q: Can I use 素墨API from China without a VPN? A: Yes. The service is hosted in China and accepts 支付宝 and 微信支付 (though payment isn’t needed). No VPN required for API calls.
Q: Does 素墨API support OpenAI-compatible SDKs? A: Yes. The API uses the standard Chat Completions format. You can swap the base URL in any OpenAI SDK client and it works.
Q: What happens if 素墨API goes down? A: Uptime is 98.0% — that’s about 7 hours downtime per month. No SLA is published. For production workloads, consider a fallback relay like OpenRouter.
Q: Can I access GPT-4 or Claude through 素墨API? A: No. Only open-weight models are available: Qwen 2.5, GLM-4, DeepSeek V3, Llama 3, and Mistral (with 30+ variants). No proprietary models.
Pricing breakdown
素墨API offers competitive pricing for developers. Here's the breakdown:
| Plan | Price | Quota | Best for |
|---|---|---|---|
| Free | $0/mo | Free trial | Kicking the tires |
| Standard RECOMMENDED | Pay-as-you-go/mo | Unlimited usage | Solo devs · small teams |
| Enterprise | Custom | SLA · dedicated support | Teams & agencies |
Supported models
5 models across major vendors.
Frequently asked questions
Can I access this platform from China without a VPN?
Most relay stations are accessible from Chinese ISPs. Check our review for specific routing details.
What payment methods are accepted?
Payment options vary by platform. Some accept Alipay/WeChat Pay, others are USD/crypto only.
How does this compare to using OpenAI directly?
Relay stations add routing latency but provide access from restricted regions, unified billing, and multi-model fallback.
Is my API key safe?
Keys are encrypted at rest. Most platforms support per-project scoping and IP allow-lists.
Should you use 素墨API?
Free forever API relay with strict no-logging policy. Handles 1B+ tokens daily with open-source model coverage.