Choose text input and encoding mode, then enter Hello exactly as shown below. Use UTF-8 and the standard Base64 alphabet for this example. Encode the text and check that the result is SGVsbG8=. Switch to decoding mode, paste that result and decode it to recover the original five characters. A trailing newline changes the encoded result.
For an integration, first check whether the receiving system expects standard Base64 or its URL-safe variant. Match its padding and line-wrapping requirements rather than changing options at random. When handling a file, use the file workflow so its bytes are encoded directly. Decoded binary data should be downloaded in the appropriate format rather than treated as readable text.
Single file uploads allow 100MB and warn above 10MB; memory use includes both original bytes and their larger encoded representation.
Hello → SGVsbG8= → Hello
btoa("Hello"); // SGVsbG8=
base64.b64encode(b"Hello") # SGVsbG8=
Base64 reversibly represents bytes using a 64-character alphabet and padding where needed. It is not encryption, secret storage, or compression. Output generally grows, and anyone holding it can decode it. Use an appropriate secure channel for credentials or sensitive information; encoding a value does not provide access control or establish who created it.
Standard Base64 uses plus and slash; URL-safe Base64 substitutes hyphen and underscore. Padding depends on the receiving format. JWT segments, data URLs, and MIME attachments are different containers, so identify the expected representation first. Do not remove arbitrary characters to force acceptance. Retain the unchanged source when diagnosing copying or transport errors.
Processing runs in your browser. Choosing Share uploads the selected tool state; anyone with the link can open it. Signing in to save sends content to your account library and records save history. Review the selection before either action. Closing the page does not delete those copies. Copying locally does not create a server share.
Check that the input is complete and uses the selected alphabet. Text decoding also needs the correct character encoding. Valid Base64 can represent an image, archive or other binary file, so unreadable text does not necessarily mean the bytes are corrupt. Use binary download when that is the intended output.
Start with a small sample and confirm a round trip before encoding a large file. The browser needs memory for both source and encoded output, and Base64 expansion adds to that cost. No fixed processing latency or guaranteed size reduction is promised. Keep the original file until the receiving application accepts the result.
Drag and drop a file here, or
Supports all file types • Max size: 100MB
Processing runs in your browser. Saving and sharing are optional, require an account, and send your chosen content to our service.
File Size Limits: Maximum file size: 100MB. Files above 10MB trigger a warning. Processing retains data in browser memory; completion depends on the device and input.