Jenee

Base64 Encoder/Decoder

Safely convert text and files to Base64 or decode Base64 back to original. All processing is done locally.

How to Use

  1. STEP 1
    Choose the Text/File tab.
  2. STEP 2
    Toggle Encode/Decode and enter input (or select a file) to get results instantly.
  3. STEP 3
    Optionally enable data URI output and set a MIME type.
  4. STEP 4
    Use Copy or Download to utilize the results.
  • All processing happens locally in the browser; no data is sent to servers.
  • Text decoding assumes UTF-8. Use the File tab for binary.
  • Very large files may stress device memory.

Tips

1

Base64 represents binary as 64 characters. Used in email and data URIs.

2

Data URI example: data:image/png;base64,.... You can embed it directly in CSS/HTML.

3

When using in URLs, URL-encode as needed.

4

The trailing = is padding. In URLs it may appear as %3D after encoding.

5

URL-safe Base64 (using - and _) differs from standard Base64 (using + and /). Choose appropriately for your use case.

6

Round-tripping text→Base64→text is safe when the encoding matches (this tool uses UTF-8).

7

Very large files can exhaust memory. Hundreds of MB may hit browser limits.

8

Data URIs are handy but can bloat HTML/CSS bundles. Consider caching implications.

FAQ

  • QUESTION 1

    Why not use btoa/atob?

    For Unicode support, we convert using TextEncoder/TextDecoder and then Base64 encode/decode.

  • QUESTION 2

    Which MIME type should I use?

    For images, use image/png or image/jpeg; for text, text/plain; charset=utf-8, etc. It works even if not specified.

  • QUESTION 3

    Can I save the decoded result as a file?

    Yes. In the File tab, you can download the decoded file.

  • QUESTION 4

    Can I paste a data URI to decode?

    Yes. The leading data:[mime];base64, is stripped automatically before decoding.

  • QUESTION 5

    Will Unicode (e.g., Japanese) break?

    The Text tab round-trips with UTF-8. If input Base64 was encoded with a different charset, you may see garbling.

  • QUESTION 6

    Is there a maximum size?

    Depends on browser and device memory. Very large inputs (hundreds of MB) can fail. Chunked streaming isn’t supported yet.

  • QUESTION 7

    Do you support URL-safe Base64?

    We accept input as-is. If needed, replace -/_ with +/ and try again to normalize.

  • QUESTION 8

    Any security caveats?

    Base64 is not encryption. Do not use it for secrecy. Use proper encryption and secure storage for sensitive data.

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