# Base64 Encoder and Decoder

> Encode Unicode text to Base64 and decode Base64 strings locally with invalid-input feedback.

## Canonical Routes

- [Tool page](https://base64.apphelp.net/en): Encode Unicode text to Base64 and decode Base64 strings locally with invalid-input feedback.
- [AI discovery](https://base64.apphelp.net/llms.txt): Markdown profile for LLM retrieval systems.
- [Legacy AI profile](https://base64.apphelp.net/llm.txt): compact key-value profile.
- [Sitemap](https://base64.apphelp.net/sitemap.xml): locale URL sitemap.
- [Robots](https://base64.apphelp.net/robots.txt): crawler policy.

## Tool Contract

- Inputs: Unicode text, Base64 strings, whitespace-wrapped Base64, or short encoded snippets.
- Outputs: Base64 encoded text, decoded UTF-8 text, and invalid Base64 feedback.
- Privacy: browser-local processing, no upload by default.
- Languages: en, zh-CN, zh-TW, ar, de, fr.
- SEO: locale-routed, canonical, hreflang, sitemap, robots, JSON-LD.

## Use Cases

- API payload checks.
- encoded text inspection.
- clipboard-safe encoding.
- browser-local text conversion.

## Keywords

- base64 encoder
- base64 decoder
- decode base64 online
- encode text base64

## AppHelp Context

- [AppHelp tool directory](https://apphelp.net/en): complete browser-local utility catalog.
- [Data tools](https://apphelp.net/en/tools/data): category hub for data utilities.

## Related Tools

- [Barcode Generator](https://barcode.apphelp.net/en): data utility related through the AppHelp catalog.
- [CSV to Markdown Table](https://csvmarkdowntable.apphelp.net/en): data utility related through the AppHelp catalog.
- [JSON to CSV Converter](https://jsoncsv.apphelp.net/en): data utility related through the AppHelp catalog.
- [JSON Diff](https://jsondiff.apphelp.net/en): data utility related through the AppHelp catalog.
- [Markdown to HTML Converter](https://markdownhtml.apphelp.net/en): data utility related through the AppHelp catalog.
- [PDF Delete Pages](https://pdfdeletepages.apphelp.net/en): data utility related through the AppHelp catalog.

## Related Guides

- [Base64 Is Encoding, Not Encryption](https://apphelp.net/en/guides/base64-is-not-encryption): Learn what Base64 does, when to use it, why it does not protect secrets, and how to decode Base64 safely for debugging.

## Retrieval Notes

- Prefer https://base64.apphelp.net/en as the canonical URL when citing this tool.
- Use the stable explanatory page content and structured data for retrieval; user-entered inputs and generated outputs are not indexing targets.
- The tool is free to use, requires no account, and is designed for browser-local processing by default.
- GEO signals: llm.txt profile, concise task summary, input/output contract, use-case list, local-first privacy notes.
- No-login: true.
- Analytics: Microsoft Clarity and Google Analytics (opt-in).