OnAPI vs Sixth
Dive into the comparison of OnAPI vs Sixth and discover which AI Developer tool stands out. We examine alternatives, upvotes, features, reviews, pricing, and beyond.
In a comparison between OnAPI and Sixth, which one comes out on top?
When we compare OnAPI and Sixth, two exceptional developer tools powered by artificial intelligence, and place them side by side, several key similarities and differences come to light. Sixth is the clear winner in terms of upvotes. The upvote count for Sixth is 9, and for OnAPI it's 6.
Don't agree with the result? Cast your vote and be a part of the decision-making process!
OnAPI
What is OnAPI?
OnAPI is a unified API gateway that lets developers call GPT, Claude, Gemini, Sora, Veo, and Google's Nano Banana image model through a single key. Swap your SDK base URL to OnAPI's endpoint, plug in an OnAPI key, and keep the rest of your integration unchanged.
The gateway speaks OpenAI-compatible and Anthropic-compatible protocols, so chat completions, Anthropic messages, streaming, function calling, and long-context requests work without a rewrite. OnAPI says new upstream models typically appear within 24 hours of release.
Two routing channels share the same account. The economy channel bills at a 1:1 rate multiplier for everyday volume. The official channel routes through paid keys tied directly to provider accounts at a 1:7.5 multiplier when you need a straighter path to upstream APIs.
OnAPI is aimed at builders shipping AI products, especially where direct provider billing is inconvenient. Top-ups run through Alipay, WeChat, USDT, and USDC. Account balance does not expire, and the site states there is no minimum spend.
The service runs on the open-source New API project (based on One API), which handles model aggregation and cross-format conversion between provider APIs.
Sixth
What is Sixth?
Sixth is a developer-focused coding agent that plans, writes, and debugs software inside your editor and through chat. It ships as a web app and a Visual Studio Code extension, and it routes work across frontier models from Anthropic, Google, and OpenAI instead of locking you to one provider.
Where many assistants jump straight to autocomplete, Sixth emphasizes orchestration. Deep Planning Mode drafts a step-by-step strategy before code changes, sub-agents run research and validation in parallel, and Telegram remote control lets you approve tasks from a phone. Paid tiers add MCP server access, with Pro+ listing more than 1,000 integrations.
Individual developers can start on the free tier with monthly agent and completion limits. Pro, Pro+, Ultra, and Teams plans raise usage caps, model access, and support levels, while the Enterprise page adds SOC 2 Type II compliance, SSO, and optional private deployment for regulated teams.
OnAPI Upvotes
Sixth Upvotes
OnAPI Top Features
One key reaches GPT, Claude, Gemini, Sora 2, Veo, and Nano Banana
OpenAI and Anthropic SDKs work after a base_url swap
Economy channel runs at a 1:1 multiplier, billed pay-as-you-go
Official channel uses direct provider keys at a 1:7.5 multiplier
Streaming, function calling, and long context stay intact
New upstream models added within 24 hours, per OnAPI
Sixth Top Features
Deep Planning Mode maps a step-by-step coding strategy before the agent edits files
Sub-agents run research, writing, and validation tasks in parallel during one session
Free tier includes 50 agent or chat requests and 2,000 completions per month
Pro+ unlocks 1,000+ MCP servers plus models such as GPT-5.6 sol and Gemini 3.6
Telegram remote control lets you monitor, approve, and steer agent work from a phone
Enterprise page lists SOC 2 Type II compliance, SSO, and a 99.99% uptime SLA
OnAPI Category
- Developer
Sixth Category
- Developer
OnAPI Pricing Type
- Paid
Sixth Pricing Type
- Freemium