Respan (formerly Keywords AI) vs ZeroGPT

Respan is an LLM engineering platform for teams shipping production AI agents and applications. Route model traffic through one gateway, trace every call in detail, run evals on offline datasets and live traffic, and monitor cost, latency, and errors from a single dashboard.

The product grew out of Keywords AI, a Y Combinator Winter 2024 company founded by engineers from the University of Illinois. What started as LLM routing expanded into full observability after customers asked for visibility into how agents behaved in production. Respan now positions itself around the loop from tracing to evaluation to iteration.

It fits ML engineers, platform teams, and AI product builders who need gateway failover, prompt version testing, production quality scoring, and spend controls without stitching together separate tools. Customers cited on the site include teams at Retell AI, Mem0, Lovable, and Gumloop.

ZeroGPT scans pasted text or uploaded files to estimate whether ChatGPT, GPT-5, Gemini, Claude, or other LLM models wrote it, highlighting AI sentences with percentage scores. The free detector handles up to 15,000 characters per check and sits inside a larger writing suite with humanizer, plagiarism, grammar, and summarizer tools.

Standalone AI detectors often flag whole documents without sentence-level detail, while plagiarism scanners ignore whether the prose itself came from a model. ZeroGPT combines DeepAnalyse highlighting, PDF detection reports, batch uploads, and companion tools like an AI image detector and ZeroCHAT assistant on the same domain.

Teachers, publishers, recruiters, and SEO teams use ZeroGPT when they need fast LLM screening before accepting submissions. Free accounts work without a card, premium MAX and EXPERT subscriptions unlock higher character limits such as 350,000 characters per scan, and pay-as-you-go API access is available for custom integrations.