Compare AI tools

	GitHub Copilot B	OpenRouter S	Cartesia S	Kling A
Tagline	Microsoft/GitHub's autocomplete. Deep VS Code + JetBrains integration.	One API, every model. Pay-as-you-go, no subscriptions.	Ultra-low-latency voice. Built for realtime agents.	Kuaishou's video model. The surprise standout.
Category	Coding	Dev Platform	Voice	Video
Pricing	Free (limited) + $10/mo Pro + $19/mo Business	Pay per token — model-dependent	Free tier + usage-based API	Credit-based, free trial
Best for	Teams with GitHub already. Devs who don't want to change IDEs.	Developers experimenting across models. Apps that want fallback logic.	Developers building voice agents, phone bots, interactive apps.	Anyone who wants top-tier video quality for less.
Strengths	Great enterprise story Works in your existing IDE Chat + autocomplete	300+ models from one endpoint Automatic fallbacks between providers No subscription — just pay what you use	< 90ms latency — the fastest in the market Sonic model sounds natural Developer-friendly API	Very strong motion + physics Often beats Runway on realism Great price
Weaknesses	Less agentic than Cursor/Claude Code Model quality varies	Slight markup over direct API Some provider features not exposed	Fewer voices than ElevenLabs Less consumer-facing brand	UX is rough for English speakers Queue times
Kai's verdict	B-tier. Solid for autocomplete but the category moved past it. Pick Cursor unless you can't.	S-tier for model-shopping. I use this for every prototype before committing.	S-tier for realtime. If latency matters more than voice catalog, start here.	A-tier. Rising fast. If you can tolerate the UX, quality per dollar is best-in-class.
Link	Open →	Open →	Open →	Open →