Base64 Decoder — Decode Base64 to Readable Text
Convert Base64-encoded strings back to readable text instantly. Decode data URIs, authentication tokens, and encoded configuration values.
How to Decode Base64
Paste Base64 String
Copy a Base64-encoded string and paste it into the input field. Common sources include data URIs, API tokens, and encoded configuration values.
Click Decode
Press the Decode from Base64 button. The browser's built-in atob() function converts the Base64 string back to its original text form.
Read the Result
The decoded text appears in the output field. Copy it for further use. If the Base64 contained binary data like images, the output may show garbled characters.
About Base64 Decoding
Base64 decoding is the reverse of Base64 encoding. The decoder takes a Base64 string, validates it against the 64-character alphabet (A-Z, a-z, 0-9, +, /), strips any padding = characters, and reconstructs the original data. Every three Base64 characters represent two bytes of original data. Modern browsers provide native atob() support, making decoding fast and reliable. This tool is especially useful for developers debugging API responses that include Base64-encoded payloads, inspecting data URIs embedded in HTML and CSS, and converting authentication tokens to their actual contents for troubleshooting. The decoder also handles common Base64 variants, including URL-safe Base64 where + and / are replaced with - and _. When decoding, the tool first attempts UTF-8 decoding for text output, which handles international characters, emojis, and special symbols correctly. If the decoded data is not valid UTF-8 text (such as encoded images or binary files), the raw byte representation is shown. For inspecting binary data, we recommend using hex dump tools alongside this decoder.