Base64 file converter

Using this tool

Convert between local file bytes and Base64.

Example

Paste the data URL and decode. Text files have no image preview; downloaded bytes spell Hello.

Example action and settings

Action: Decode
Filename: demo.txt
MIME type: text/plain

data:text/plain;base64,SGVsbG8=

Decoded 5 bytes · text/plain; downloaded demo.txt contains Hello.

Scope and limitations

• Each file is limited to 32 MiB; only common raster images are previewed, never executable SVG/HTML.
• Accepts standard Base64, not Base64URL; invalid padding and noncanonical trailing bits are rejected.

Common mistakes

• MIME and filename extensions do not convert file contents; a data URL supplies its own MIME instead of the raw-Base64 MIME field.

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Privacy and browser support

Input is processed in this browser. Do not use real keys or active sensitive credentials as demonstration data. Device features require browser support and your permission.