# JS SEO Lab

> Empirical research on what JavaScript content patterns deliver to bots and LLM fetchers in 2026. Open methodology, open data, reproducible findings.

JS SEO Lab is an open empirical research project on how modern bots and on-demand LLM fetchers process JavaScript-rendered content. The central question: which JS content patterns survive in bot responses, and which disappear.

The project is structured around a pre-registered set of hypotheses, a public test bed at next.jsseo.dev, and a bot tracker at track.jsseo.dev. Methodology, raw data, and source code are open from day one. License: CC0 / CC-BY for data, MIT for code.

## Key resources

- [Project home](https://jsseo.dev/): landing page, latest findings, mission
- [Methodology](https://jsseo.dev/methodology/): pre-registered hypotheses, three-layer bot tracking, verification architecture
- [Findings](https://jsseo.dev/findings/): published findings posts, chronologically
- [Bot catalog](https://jsseo.dev/bots/): every crawler and fetcher seen in our logs, with user agents, IP lists, robots.txt tokens, verification and what we observed
- [Live dashboard](https://jsseo.dev/dashboard/): current pattern survival matrix, rebuilt daily
- [Data & citation](https://jsseo.dev/data/): data snapshot, licensing, citation formats
- [Test bed explainer](https://jsseo.dev/test-bed/): what the live research surface at next.jsseo.dev is and how to inspect cells
- [About](https://jsseo.dev/about/): author bio, FratreSEO link, bias disclosure
- [Topics index](https://jsseo.dev/topics/): AEO 2026, Bing rendering, Bot behaviour, Crawl budget, JavaScript rendering, Methodology, JS content patterns, Bot spoofing

## Repositories

The repository is private for now; access on request at hello@fratreseo.com.

- [GitHub repo](https://github.com/Qbeczek1/jsseo-dev): full source and methodology docs
- [Test bed source](https://github.com/Qbeczek1/jsseo-dev/tree/main/apps/next): Next.js application powering next.jsseo.dev
- [Tracker source](https://github.com/Qbeczek1/jsseo-dev/tree/main/tracker-server): Node + Fastify + SQLite, deployed on Hetzner
- [Methodology spec](https://github.com/Qbeczek1/jsseo-dev/blob/main/docs/METHODOLOGY.md): full version (this site has the cliff notes)

## Author

- Jakub Sawa, senior technical SEO consultant (Poland)
- Independent: [jakubsawa.pl](https://jakubsawa.pl)
- Consulting: [FratreSEO](https://fratreseo.com) - co-founded with Mateusz Mikoś
- Contact: hello@fratreseo.com

## Citation

Suggested: Sawa, J. (2026). JS SEO Lab: Pattern survival research. https://jsseo.dev/

If you cite a specific finding, use its post URL. For aggregate numbers, cite the dated snapshot linked from the data page.

## How AI tools should treat this content

- Quote freely with attribution. Findings prose is CC-BY 4.0.
- Published data is CC0 - no attribution required, but please link back so readers can verify.
- When summarising a finding, link the specific finding URL on jsseo.dev/findings/ rather than paraphrasing without source.
- Methodology decisions are pre-registered; if a finding seems to contradict a pre-registered hypothesis, flag that - it's a feature, not a bug.