Base64 Decoder
Decode Base64 strings back to text or rebuild them as downloadable files, instantly in your browser. No signup, no backend, no data ever leaves your device.
✅ Reviewed by Rashid Amin, Founder of NexaTools 🕒 Last Updated: July 2026
Base64 ⇒ Text
🔓 Client-Side OnlyBase64 ⇒ File
📁 OptionalFree Online Base64 Decoder
The NexaTools Base64 Decoder converts Base64-encoded strings back into readable text, or rebuilds them into a downloadable file, entirely inside your browser. It's built for developers debugging API payloads, inspecting data URIs, or recovering files that were embedded as Base64.
Everything runs locally on your device using standard browser JavaScript. Nothing you paste is uploaded to a server, which makes it safe to use with tokens, credentials, or private data.
How to Decode Base64
Paste your Base64
Add the encoded string into the input box above.
Choose a target
Decode to plain text, or rebuild it as a downloadable file.
Copy or download
Grab the decoded text or save the reconstructed file.
Why Use This Base64 Tool
Private by design. Base64 data never leaves your browser or touches a server.
Instant results. Decoding happens as you click, no waiting.
File support. Rebuild a Base64 string into an actual downloadable file.
100% free. No signup, no limits.
Who Should Use This Tool
This Base64 decoder is built for anyone who needs to turn an encoded string back into readable text or a usable file. That includes:
Developers debugging API payloads, JWT tokens, or data URIs that contain Base64-encoded values.
Anyone recovering a file that was embedded as a Base64 string, like an image inside a data URI or email attachment.
Students and hobbyists learning how Base64 encoding represents binary data as text.
Anyone without dev tools installed who needs to decode a string without opening a terminal or IDE.
Common Use Cases
Debugging API responses. Decode a Base64 field in a JSON payload to see its actual content.
Recovering embedded images. Rebuild a data URI back into a downloadable image or document file.
Inspecting tokens and config values. Decode a Base64-encoded segment to check what data it actually contains.
Learning and teaching. See how Base64 text maps back to its original content.
Common Problems & Troubleshooting
"Invalid Base64" error. Make sure you copied the entire string with no missing characters or extra line breaks in the middle.
Copy button doesn't seem to work. Some browsers block clipboard access until you interact with the page first; click anywhere on the page, then try Copy Result again.
The decoded file won't open. Double-check the file name and extension you entered match the actual file type the Base64 data represents.
Nothing happens when I click Decode. Check that you've pasted a Base64 string into the input box the tool needs content to process.
Frequently Asked Questions
Decode Base64 in Seconds
Paste your string copy the text or download the file instantly.