# CalcDuo

> Fast, free online calculators, converters, finance tools, health tools, SEO tools, file utilities and everyday web tools.

## Crawling Policy

Public pages are available for search engines and AI crawlers. Admin, API and embed paths are not intended for crawling.

## Sitemaps

- [Sitemap](https://calcduo.com/sitemap.xml)

## Language Home Pages

- [English](https://calcduo.com)
- [Spanish](https://calcduo.com/es)
- [Portuguese](https://calcduo.com/pt)
- [German](https://calcduo.com/de)
- [French](https://calcduo.com/fr)
- [Arabic](https://calcduo.com/ar)

## Key Pages

- [Home](https://calcduo.com)
- [Finance tools](https://calcduo.com/category/finance)
- [Health tools](https://calcduo.com/category/health)
- [File converters](https://calcduo.com/category/file-converters)
- [Image tools](https://calcduo.com/category/image-files)
- [JPG format hub](https://calcduo.com/format/jpg)
- [PDF format hub](https://calcduo.com/format/pdf)
- [MP4 format hub](https://calcduo.com/format/mp4)
- [SEO tools](https://calcduo.com/category/seo)

## Representative Tools

- [Crypto If Bought Calculator](https://calcduo.com/crypto-if-bought-calculator)
- [What If I Invested Calculator](https://calcduo.com/what-if-i-invested-calculator)
- [Subscription Cost Calculator](https://calcduo.com/subscription-cost-calculator)
- [File Compressor](https://calcduo.com/file-compressor)
- [PDF Toolkit](https://calcduo.com/pdf-toolkit)
- [JPG to WEBP Converter](https://calcduo.com/jpg-to-webp)
- [DOCX to PDF Converter](https://calcduo.com/docx-to-pdf)
- [MP4 to MP3 Converter](https://calcduo.com/mp4-to-mp3)
- [SEO Audit Tool](https://calcduo.com/seo-audit-tool)

## File Conversion API Safety

- Contract: [OpenAPI](https://calcduo.com/openapi.json)
- Keep the create response accessToken only in memory and send it as an Authorization Bearer header for status, cancellation, and the one-time download.
- Never put the token in a URL, query string, log, or persistent storage.