AI and data-based HR tech platform JobKorea, operated by WorkSphere, said on Oct. 27 it analysed detailed job posting descriptions over the past six years and confirmed a trend in which companies are making job information and hiring conditions in postings more specific.

The company attributed the shift to changes in the capabilities required for each job as AI spreads.

JobKorea said it examined the number of characters, including spaces, item structure and key keywords for postings published from 2021 through the third quarter of this year where the main text of the detailed description could be extracted.

A notable change was in the "preferred qualifications" section. The share of postings that included a preferred qualifications item in the body text rose to 28.3 percent this year from 14.5 percent in 2021, nearly doubling. The share of postings that included a "requirements" item also rose, to 27.3 percent from 18.6 percent. From 2025, the share with preferred qualifications surpassed the share with requirements.

Postings also became longer. The median posting length increased 79 percent to 864 characters this year from 483 characters in 2021. The average rose 32 percent to 1,077 characters from 817 characters. The median rose every year through 2025, when it reached 881 characters, and stayed at a similar level this year.

Postings that mention AI-use capabilities are also rising quickly. Postings that included related keywords such as "AI use," "generative" and "prompt," or AI tool names such as ChatGPT, Claude and Gemini, rose 198 percent in January to September from the same period a year earlier. Their share of all postings increased to 1.92 percent this year from 0.37 percent in 2024. The share is still around 2 percent, but the growth rate is steep, JobKorea said.

These postings also tended to have more finely segmented hiring conditions. Among postings that included AI-use keywords, 50.8 percent had a separate preferred qualifications section. Classification is also becoming more diverse. JobKorea expanded its AI job categories last year to 12 from one, including AI planner, prompt engineer and MLOps engineer.

A JobKorea official said, "With the adoption of AI, the capabilities expected can differ even for the same job." The official added, "It has become more important for companies to specify job content and preferred conditions in more detail, and for job seekers to show their capabilities in line with those criteria."