How to encode or decode Base64 for free
To encode text or files to Base64, open the ToolCrix Base64 Encoder, type or drop your content, and click Encode. To decode, paste a Base64 string and click Decode. Everything runs in your browser — your data is never uploaded.
Need to encode something to Base64 or decode a Base64 string? This guide explains what Base64 is, when to use it, and how to do it for free in your browser with no upload and no sign-up.
What is Base64 encoding?
Base64 converts binary data (images, bytes, files) into a plain ASCII string of 64 safe characters: A–Z, a–z, 0–9, + and /. It's used everywhere in computing: embedding images in HTML via data URIs, encoding credentials for HTTP Basic Auth, transmitting binary data in JSON, encoding email attachments (MIME), and storing complex data in text-only formats.
Importantly, Base64 is encoding, not encryption — anyone can decode it back. It just makes binary data safe to transport through text-only channels.
How to encode or decode Base64 (step by step)
- Open the Base64 Encoder/Decoder.
- Type or paste your text, or drop a file.
- Click Encode to convert to Base64, or Decode to convert Base64 back to its original form.
- Copy the result.
When to use Base64
- Embedding small images in HTML/CSS —
data:image/png;base64,iVBORw...saves an HTTP request for tiny icons. - HTTP Basic Authentication —
Authorization: Basic base64(user:pass). - JSON data transport — send binary data through APIs that only accept text.
- JWT tokens — the header and payload sections are Base64-encoded JSON.
- Email attachments — MIME uses Base64 to encode attachments safely.
Does Base64 increase file size?
Yes — Base64 adds about 33% overhead because each 3 bytes of input become 4 characters of output. That's why it's best for small payloads and not for compressing large files.
Frequently Asked Questions
Is Base64 encryption?
No. It's encoding — anyone can decode it back to the original data. Do not rely on Base64 for security.
Can I encode files?
Yes, drop any file and its Base64 string is generated instantly in your browser.
Is my data uploaded?
No, all encoding and decoding runs locally in your browser.
Is it free?
Yes, completely free with no sign-up.
Try it now: open the free Base64 Encoder/Decoder, or browse more developer guides.