AI's Growing Influence on Y Combinator Applications: Length, Style, and Controversy

The startup accelerator Y Combinator has observed a notable increase in the length of its applications over the past three years, a phenomenon some partners attribute to the growing use of artificial intelligence in drafting responses. Distinctive linguistic patterns, such as the pronounced use of em dashes and specific vocabulary, are emerging as potential indicators of AI-assisted writing, sparking a discussion among YC’s leadership about the role of AI in founder communications.
The AI Imprint on Startup Submissions
In recent years, applications submitted to Y Combinator have seen a significant increase in their overall word count. According to Tyler Bosmeny, a YC partner, the length of these submissions has expanded by 60% over the last three years. This surge has led to speculation that applicants are increasingly leveraging AI writing tools to articulate their ideas regarding business concepts, competitive landscapes, and revenue models.
Pete Koomen, another YC partner, noted a shift in writing style, remarking on the unusual phrasing found in contemporary applications compared to those from just a year prior. He highlighted the rising frequency of certain words, such as “wedge,” which appeared in less than 1% of applications in spring 2025 but surged to over 20% by summer 2026. Simultaneously, the use of em dashes – particularly those framed by spaces – also saw a dramatic rise, appearing in over half of all YC applications by summer 2025. This latter trend, Koomen suggests, aligns with the launch of advanced AI models like Anthropic’s Opus 4, indicating a potential correlation between AI tool availability and stylistic changes in applications. Interestingly, another word often linked to AI-generated text, “delve,” experienced a brief spike in early 2024 but never reached significant prevalence, suggesting that AI’s linguistic fingerprints can vary.
The debate within YC regarding AI-assisted writing is not without nuance. Garry Tan, the current CEO, has openly admitted to using AI for his own writing, viewing it as a “high-bandwidth conversation” that helps refine ideas. He believes that any shortcomings in AI-generated text can be “fixed” by human oversight. Conversely, YC co-founder Paul Graham holds a more skeptical view. He has expressed discomfort with emails from founders that exhibit a “hard-hitting journalistic style,” which he identifies as characteristic of AI. Graham finds such submissions disingenuous, likening the experience to being deceived. His criticism extends to specific vocabulary, like the word “delve,” which he considers a tell-tale sign of ChatGPT usage. Despite these differing opinions, Y Combinator continues to support startups that specialize in AI-generated writing, reflecting a broader acceptance of AI within the tech ecosystem.
The evolving landscape of Y Combinator applications underscores a broader conversation about the integration of artificial intelligence into creative and professional processes. While AI tools can enhance efficiency and refine expression, their pervasive use raises questions about authenticity, originality, and the value of human-centric communication. For founders, the challenge lies in leveraging AI effectively without sacrificing their unique voice and genuine passion. For accelerators like YC, it prompts a reevaluation of assessment criteria and an adaptation to new forms of applicant engagement. This trend invites us to consider how technology shapes not only our work but also our perception of integrity and innovation in the competitive world of startups.