Base64 Encoder / Decoder
Encode text to Base64, decode Base64 back to text, or convert any image to a Base64 data URL. Instant, private, free.
Encode & Decode Base64 Instantly
Base64 is a binary-to-text encoding scheme widely used in email, data URIs, JWTs, and API payloads. Zolkit's encoder/decoder runs entirely in your browser — nothing is ever uploaded to a server.
100% Private
All encoding and decoding happens locally in your browser using native Web APIs. Your text and images never leave your device.
Instant Conversion
Results update in real time as you type. No button to press, no page reload — just instant output.
Image to Data URL
Drop any PNG, JPG, GIF, WebP, or SVG file to get a Base64 data URL you can embed directly in HTML or CSS.
Unicode Support
Handles multi-byte Unicode characters correctly, so emojis and non-ASCII text encode and decode without corruption.
Free Forever
No account, no signup, no watermarks. Zolkit is completely free to use.
Image Preview
See a live preview of your image alongside the generated Base64 data URL, with file size information.
How to Encode or Decode Base64
- 1
Switch to the Text tab, choose Encode or Decode mode, then paste your content into the input box.
- 2
The output appears instantly. Copy it with the Copy button.
- 3
For images, switch to the Image tab and drop a file (max 2 MB) to get its Base64 data URL.
Frequently Asked Questions
What is Base64 encoding?
Base64 is a binary-to-text encoding that represents binary data using 64 printable ASCII characters. It is used wherever binary data must be stored or transmitted as text — for example in data URIs, email attachments, JWT tokens, and API responses.
Does this tool support Unicode and emoji?
Yes. The encoder uses encodeURIComponent before btoa to correctly handle multi-byte characters. The decoder reverses the process, so any Unicode text (including emoji) round-trips without corruption.
What image formats can I convert to Base64?
PNG, JPG/JPEG, GIF, WebP, and SVG are all supported. The tool uses the FileReader API to read the file and produces a data URL in the format data:[mime];base64,[data].
Is there a size limit?
For images the limit is 2 MB, which is generous for embedded use cases. Text input has no enforced limit beyond your browser's available memory.
Can I embed the Base64 data URL directly in HTML?
Yes. Use it as the src of an <img> tag or as a CSS background-image URL. This eliminates an HTTP request, which can be beneficial for very small images like icons.
Are my files or text sent to your servers?
No. Everything runs in your browser using btoa/atob and the FileReader API. We have no server-side processing for this tool.