The market added 486k new ads.txt lines and removed 425.6k, producing a net of +60.4k. Both direct and reseller entries grew, with resellers accounting for 57.4% of gross additions.
- Resellers driving 57.4% of gross additions signals that SSPs are still onboarding publishers through intermediary paths rather than establishing direct relationships, a pattern that directly inflates auction duplication risk for Established SSPs already carrying a 46% duplicated-domain rate.
- The direct segment netted +21.3k, showing publishers are not just maintaining existing direct relationships but actively forming new ones. For SSPs focused on direct coverage, this is the most open onboarding window since February.
The changes in the ads.txt lines show notable improvements compared to previous months. Here are some top SSPs that have gained a good number of new lines.
- Onetag led all SSPs at +13.8k lines, nearly 4x last month’s top SSP gain. This follows Onetag’s acquisition of creative tech platform Aryel and 34% net revenue growth in 2025, making it the most active SSP in publisher onboarding. Its AI-driven curation model gives publishers pre-scored deal packages that work without third-party cookies.
- Seedtag and Risecodes ranked fourth and fifth with near-identical gains. Both are contextual specialists, and their presence in the top five confirms that publishers are actively adding cookieless-ready partners, not waiting for cookie deprecation to act.
Want to know more? Please download the full report for a detailed breakdown.
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