Base64 Converter

Encode/decode text or files to Base64

Input

Output

aGVsbG8gd29ybGQ=

How it works

Base64 Converter — Encode/decode text or files to Base64. All processing happens in your browser — no upload, no signup, no email required. Free forever.

Last updated: 2026-05-06

Editor's note

Encoding is not encryption. We say it a lot because the most common Base64 misuse we see in code reviews is people "obfuscating" API keys inside a client-side bundle, as if a stranger with a browser console couldn't decode it in five seconds. The tool exists for the legitimate cases — embedded data URIs, inspecting the middle segment of a JWT, wrapping a binary into a YAML string — and we deliberately resisted adding any feature that would let someone lie to themselves about secrecy.

The file mode came after we kept watching people copy-paste long Base64 blobs out of webhook payloads and accidentally mangle line endings or pick up a smart quote from a chat client. Now you drop the file in and the encoded text either comes out clean or the decoder tells you exactly which character is invalid. The Invalid Base64 message points at the position, not just "something is wrong", because the difference between a stray newline and missing padding actually matters.

About Base64 Converter

Base64 Converter encodes any text or file into Base64 and decodes Base64 strings back into the original bytes. Base64 kodlama çözme is a daily chore for developers working with email attachments, JWT payloads, data URIs and HTTP basic auth — this tool removes the command-line step.

Encode a small image to embed it as a data URI in CSS, decode a Base64 blob from a webhook to inspect its contents, or wrap a binary file as text so it can be pasted into a YAML config.

Encoding and decoding both run in your browser. Sensitive payloads — auth tokens, private keys, PII — never leave your device, so the tool is safe for confidential data.

How to use Base64 Converter

Choose the mode: Text to encode/decode plain strings, or File to convert binary files.
Pick a direction: Encode (→ Base64) to convert into Base64, or Decode (Base64 →) to convert back.
In Text mode, paste your input — the output updates instantly. In File mode, click Pick a file (or Pick a Base64 text file) to load it.
If you see an Invalid Base64 message during decoding, double-check that the input contains only valid Base64 characters and proper padding.
Use the Copy button to grab the result, or — for decoded files — let the browser download the reconstructed binary automatically.

Common use cases

Embedding a tiny logo in CSS as a data:image/png;base64,… URI to avoid an extra HTTP request.
Decoding a JWT payload by Base64-decoding the middle segment between the dots.
Wrapping a PFX certificate or a binary kubeconfig so it can sit safely inside a YAML string.
Crafting an HTTP Authorization: Basic header by encoding "username:password".
Inspecting webhook payloads where binary attachments are delivered as Base64 strings.

Tips & common mistakes

Base64 inflates the byte size by ~33%. A 100 KB image becomes ~133 KB of text — fine for tokens, expensive for large media.
Standard Base64 uses + and /; URL-safe Base64 uses - and _. Convert between them by simple character replacement before decoding.
Watch out for line breaks pasted from emails — strip them before decoding, otherwise some decoders complain.
For binary roundtrips, prefer the File mode over copy-pasting text: copy-paste can silently mangle whitespace and encoding.

Frequently asked questions

What is Base64 used for?

Encoding binary data (images, files) as ASCII text so it can be embedded in JSON, HTML, emails, or other text-only protocols.

Can I encode any file?

Yes. Pick a file in 'File' mode and click encode. The result is text you can copy or download as .txt.

How big is the encoded output?

Roughly 33% larger than the source. A 100 KB image becomes ~133 KB of Base64 text.

Is Base64 a form of encryption?

No. Base64 is an encoding, not encryption — anyone can decode it back to the original. Use it to safely transport binary as text, never to hide secrets.

What does the trailing = sign mean?

Padding. Base64 outputs in blocks of 4 characters; if the source isn't a multiple of 3 bytes, one or two = signs pad the last block. Stripping the padding can break strict decoders.

Can I encode a file directly to a data URI?

Yes — encode the file in File mode, then prepend the appropriate prefix like data:image/png;base64, to the result. The prefix tells the browser the MIME type.