Base64 Encode/Decode
Encode and decode UTF-8 text in your browser.
This runs in your browser. Nothing is uploaded.
Drop a file here or choose oneChoose file
Standard and URL-safe Base64
Standard Base64 uses + and / with padding. URL-safe Base64 uses - and _ and accepts missing padding, so choose the alphabet your receiving system expects.
Your text stays in this browser. TheDevTab does not upload or receive your input, and the tool keeps working after the page loads.
Base64 is an encoding, not encryption
Base64 changes bytes into printable characters so systems can move data through text-oriented fields. It does not hide the data and it does not prove who created it. Anyone with the encoded value can decode it. Do not use Base64 as a password format, access control, or replacement for encryption. If a value must be confidential, use an encryption design with key management.
Text input is converted as UTF-8. Accented characters, symbols, and non-Latin scripts are first represented as UTF-8 bytes, then encoded. Dropped files are encoded from their original bytes, and decoding can download binary output. If another system expects a legacy character set or raw binary, confirm its contract before treating the result as interchangeable.
Padding and URL-safe values
Standard Base64 uses an alphabet with 64 characters. It uses + and/, and adds one or two = characters when the input does not fill a complete group of three bytes. URL-safe Base64 replaces + with - and/ with _. Some token formats omit the padding, so use the mode your receiving system documents instead of switching based on appearance.
JWT segments use Base64url for their header and payload. A JWT is still not encrypted just because those segments look unfamiliar. Use the JWT Decoder to inspect a token locally, and keep the signature and verification distinction clear.
Check what the receiving system expects
Base64 output is longer than the original bytes, often by about one third. It is useful for transport, fixtures, and small text values, but it is not a compression format. Watch for whitespace added by copied values and for systems that require or reject padding. The tool processes the value in your browser and reports invalid input instead of sending it elsewhere.
FAQ
Does Base64 Encode/Decode upload my text?
No. Encoding and decoding run in your browser. After the page loads, it still works in airplane mode. TheDevTab never receives your text.
What is standard Base64?
Standard Base64 uses the plus (+) and slash (/) characters and includes padding when needed. Use it when another system expects the standard alphabet.
What is URL-safe Base64?
URL-safe Base64 replaces plus with a hyphen and slash with an underscore. This mode accepts missing padding for values used in URLs, tokens, and filenames.
Does Base64 encrypt text?
No. Base64 is an encoding, not encryption. Anyone who has the encoded value can decode it, so do not use it to protect secrets.
How does Base64 handle non-ASCII text?
The tool encodes text as UTF-8 before converting it to Base64. That means characters such as accents and non-Latin scripts can roundtrip without first converting them to a legacy code page.
What does Base64 padding mean?
Standard Base64 uses one or two equals signs when the input length does not divide evenly into three bytes. URL-safe values can omit that padding when the receiving system permits it.