Base64 locally encode and decode

Differentiate text and binaries correctly

For text, UTF-8 is first used, so that umlauts and emojis are correctly encoded. A file is read in as an unchanged byte sequence. When decoding, the tool checks whether valid UTF-8 text is available. Otherwise, a Hex preview will appear; the download will still contain all original bytes. No documents, scripts or images are executed from the input.

Standard Base64, Base64URL and Data URIs

Standard Base64 uses, among other things, plus and slash. The URL-safe variant replaces this with minus and underscore and omits the padding here. For a generic data URI, application/octet-stream is used. When decoding, the tool detects both alphabets and Base64 data URIs; mixed alphabets and invalid padding bits are reported as errors.

Base64 is not encryption

The coding makes data transportable, but does not protect it from reading. A Base64 value can be converted back without a secret key. Confidential information requires access protection and, where appropriate, genuine encryption. The generator does not require an external service and does not transfer your input.

Sizes and usage on the web

Base64 typically magnifies data by about a third. Long-embedded files can inflate HTML or CSS unnecessarily and cannot be cached independently. Use data URIs specifically. Text and file inputs are limited to 500 KB; when decoding, the limit applies to the encoded input text.

Frequent questions