# API2D vs Flatkey

API2D records 214 monthly visits with -91.3% month-over-month growth and Paid pricing. Flatkey records 49,134 monthly visits with -40.8% growth and Paid, Contact for Pricing pricing.

| Metric | [API2D](https://openaitools.app/tool/api2d-com) | [Flatkey](https://openaitools.app/tool/flatkey-ai) |
| :--- | :--- | :--- |
| Website URL | https://www.api2d.com | https://flatkey.ai |
| Categories | AI API, Large Language Models (LLMs), AI Developer Tools | AI API, AI Developer Tools, AI Models, Large Language Models (LLMs) |
| Pricing Model | Paid | Paid, Contact for Pricing |
| Monthly Visits | 214 | 49,134 |
| MoM Growth Rate | -91.3% | -40.8% |
| Primary Market | Taiwan | China |
| Direct Visits | 86 | 30,531 |
| Review Score | 3.8 | 4.1 |
| Saved Count | 4 | 0 |
| Supported Platforms | Website | Website |

## API2D

API2D is a payment-and-routing layer that sits in front of the world's major language and image models. Instead of managing billing with each provider separately, you register an API2D account, top it up, copy the issued key and paste it into any client that supports a custom API base URL. Because the interface mirrors OpenAI's own specification, most existing tools, SDKs and self-hosted chat UIs work without code changes.

The platform bills in points (P) rather than a fixed monthly subscription, so cost tracks actual token consumption. According to API2D's own documentation, overall pricing is kept at roughly 1.5x the underlying provider's official rate, with a minimum per-request charge and free cached responses. Streamed GPT-4 replies are billed differently because they hold a connection open, and media-heavy endpoints add a modest bandwidth fee.

Beyond pure relay, API2D layers on value that a raw endpoint does not offer: response caching, retrieval-augmented search, drawing tools and an agent/reseller program that lets larger accounts create and price their own sub-keys. It is aimed at Chinese-speaking developers and enthusiasts who want frictionless, domestically payable access to frontier models. For anyone evaluating it, remember that API2D is an independent third party and not affiliated with OpenAI, Anthropic or the other model vendors.

**Pricing & Plans:** Pay-as-you-go in points (P); overall cost roughly 1.5x official provider pricing, with free cache hits and a minimum per-call charge. Recharge via WeChat, Alipay, Chinese bank cards or Stripe. Points expire 180 days after your last top-up.

- **OpenAI-compatible endpoint:** One base URL and key work with virtually any app, SDK or self-hosted chat client that supports a custom API address.
- **Multi-provider model access:** Route requests to OpenAI models, Claude, Stability diffusion, Azure TTS and vector database services from a single account.
- **Points-based billing:** Consumption is metered in points with a published multiplier, so you pay for what you use rather than a flat subscription.
- **Free response caching:** Identical request bodies return cached answers for free for 24 hours, and a header can disable caching when freshness matters.
- **Reseller and grouping tools:** Larger accounts can batch-create keys, set default models and resell access through their own pricing pages.

**Strengths:** Works with the large ecosystem of OpenAI-compatible tools out of the box; Point-based billing means low commitment and granular cost control; Response caching can make repeated queries effectively free; Built-in enhancements (search, knowledge base, drawing) go beyond a plain relay

**Limitations:** Cost runs above direct provider pricing once the multiplier applies; Points expire 180 days after the last top-up, so balances need periodic renewal; No monthly plan — heavy users must estimate spend from token usage; Pricing calculation is complex because of minimum charges and bandwidth fees

[Profile (Markdown)](https://openaitools.app/tool/api2d-com.md)

## Flatkey

Flatkey positions itself as a drop-in replacement for the base URL you already use. Because the endpoint is OpenAI-compatible, an existing SDK or code path usually keeps working after you swap the URL and paste a Flatkey key. Model selection happens per request through the model ID, which means switching between labs does not require a new account, new keys, or new integration code.

Beyond raw chat completions, Flatkey aggregates utility and creation tools behind the same auth layer. Governance features are aimed at teams running agents in production: hierarchical sub-keys carry their own budgets, model allowlists, and tool permissions, and a ledger API records usage per request so spend can be attributed to a specific agent or project. A published service level agreement, channel-class failover, and the promise that Flatkey-side errors are not billed are the commercial core of the pitch.

The site advertises discounts on featured models against official list pricing, hourly verification that requests reach genuine lab endpoints, GDPR-related commitments, and zero retention of request payloads. Pricing is not published as fixed tiers, so prospective customers are expected to sign up free or contact sales for volume terms.

**Pricing & Plans:** Paid gateway with prepaid balance billing; the site pushes a free trial and directs larger buyers to sales. No fixed public plan tiers are shown on the homepage, and model prices are listed per million tokens against official list rates.

- **One OpenAI-compatible endpoint:** Point your existing SDK at Flatkey's router URL and select models by ID instead of managing a credential per provider.
- **Unified model and tool routing:** Frontier chat models and 1,000+ pay-per-call tools share one auth layer, one balance, and one invoice.
- **Sub-keys with budgets and allowlists:** Issue scoped keys per agent or environment, capped by spend and restricted to approved models and tools.
- **Automatic failover and a published SLA:** Requests route across five channel classes; when one degrades the router reroutes, backed by a 99.5% SLA document.
- **Per-request ledger and zero-charge failures:** Every call gets a request ID and usage record, and errors caused on Flatkey's side are billed at $0.

**Strengths:** OpenAI-compatible interface means minimal migration effort; Single balance and invoice across models and utility tools; Budgeted sub-keys and allowlists suit multi-agent production setups; Failed calls on the provider side are not charged, per the stated SLA

**Limitations:** No fixed public pricing tiers, so budgeting requires a sales conversation; Routing layer adds a dependency between your app and the model labs; Value depends on the discount and reliability claims holding up in practice

[Profile (Markdown)](https://openaitools.app/tool/flatkey-ai.md)

## Frequently Asked Questions

### How do API2D and Flatkey compare in monthly traffic?

API2D has 214 monthly visits, while Flatkey has 49,134. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

API2D has a month-over-month growth rate of -91.3%; Flatkey has -40.8%.

### How does pricing compare?

API2D: Paid. Pay-as-you-go in points (P); overall cost roughly 1.5x official provider pricing, with free cache hits and a minimum per-call charge. Recharge via WeChat, Alipay, Chinese bank cards or Stripe. Points expire 180 days after your last top-up. Flatkey: Paid, Contact for Pricing. Paid gateway with prepaid balance billing; the site pushes a free trial and directs larger buyers to sales. No fixed public plan tiers are shown on the homepage, and model prices are listed per million tokens against official list rates.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [OpenAI Platform](https://openaitools.app/tool/openai) | 234,678,639 | -9.6% | Paid | Enterprise developer platform and API for deploying GPT-6 Astra, Sol, Luna, and realtime multimodal agents. | [.md](https://openaitools.app/tool/openai.md) |
| 2 | [OpenRouter](https://openaitools.app/tool/openrouter-ai) | 19,941,437 | -6.2% | Paid | One API key for hundreds of AI models from every major provider | [.md](https://openaitools.app/tool/openrouter-ai.md) |
| 3 | [OrcaRouter](https://openaitools.app/tool/orcarouter) | 975,300 | -5.2% | Freemium | One OpenAI-compatible gateway for adaptive LLM routing, guardrails, and spend control | [.md](https://openaitools.app/tool/orcarouter.md) |
| 4 | [CometAPI](https://openaitools.app/tool/cometapi) | 602,966 | +49.7% | Pay-as-you-go (credits) | One OpenAI-compatible API key for 500+ AI models | [.md](https://openaitools.app/tool/cometapi.md) |
| 5 | [LiteLLM](https://openaitools.app/tool/litellm) | 576,967 | +7.9% | Freemium, Contact for Pricing | One open-source AI gateway for 100+ LLM providers | [.md](https://openaitools.app/tool/litellm.md) |
| 6 | [EvoLink AI Model API](https://openaitools.app/tool/evolink-ai-model-api) | 312,573 | -27% | Free Trial, Paid, Contact for Pricing | One API for LLM, image, video, and audio models in production | [.md](https://openaitools.app/tool/evolink-ai-model-api.md) |
| 7 | [OfoxAI](https://openaitools.app/tool/ofoxai) | 239,718 | +12.7% | — | One API key, 100+ LLMs, official pricing with no platform markup | [.md](https://openaitools.app/tool/ofoxai.md) |
| 8 | [AiHubMix](https://openaitools.app/tool/aihubmix) | 238,455 | -16.1% | Contact for Pricing | One API key for hundreds of AI models | [.md](https://openaitools.app/tool/aihubmix.md) |
| 9 | [APIMaster](https://openaitools.app/tool/apimaster) | 210,182 | +46.3% | Paid | One OpenAI-compatible key for discounted GPT, Claude and Gemini access | [.md](https://openaitools.app/tool/apimaster.md) |
| 10 | [LLM Gateway](https://openaitools.app/tool/llm-gateway) | 168,426 | -14.5% | Freemium, Contact for Pricing | One OpenAI-compatible API to route, monitor and control 250+ LLM models | [.md](https://openaitools.app/tool/llm-gateway.md) |

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Source: https://openaitools.app/compare/api2d-com-vs-flatkey-ai

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