# Resources — guides & free tools for Meta advertisers

> Guides, free tools, and playbooks for Facebook & Instagram advertisers and agencies, from the team building Harry.

## Guides

- [Facebook & Instagram Ad Specs and Sizes (2026)](https://www.useharry.com/resources/facebook-ad-specs): The complete, current reference for Facebook and Instagram ad sizes, aspect ratios, character limits, and placements — for image, video, and carousel ads. [Markdown](https://www.useharry.com/resources/facebook-ad-specs.md)

## Free tools

- [Ad mockup generator](https://www.useharry.com/tools/facebook-ad-mockup-generator)
- [ROAS calculator](https://www.useharry.com/tools/roas-calculator)
- [UTM builder](https://www.useharry.com/tools/utm-builder)
- [Ad naming generator](https://www.useharry.com/tools/ad-naming-generator)

## More

- Blog: https://www.useharry.com/blog
- Compare Harry: https://www.useharry.com/compare

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This is the Markdown version of https://www.useharry.com/resources, provided for AI agents and LLMs. Every public page has a Markdown twin — append `.md` to its URL. Full index: https://www.useharry.com/llms.txt