Base64 Decoder
Decode Base64 encoded strings back to plain text instantly. Handles standard and URL-safe Base64, auto-fixes padding, and optionally formats JSON output.
✅ Free ⚡ Live 🔍 JSON Format 🔒 Private
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Base64 Decoder ⚡ Live⚡
Live Decoding
Paste Base64 and the decoded text appears immediately — no button click needed.
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Auto-fix Padding
Handles URL-safe Base64 (- _ variants) and missing = padding automatically.
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JSON Formatter
If the decoded content is JSON, format it with one click for readable output.
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100% Private
All decoding runs in your browser using the built-in atob() API.
⭐ User Reviews
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Ryan T.
1 week ago
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The live mode is a game changer. See the encoded output update in real time as you type — no button needed.
Encoder ToolsK
Kira M.
2 weeks ago
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More reliable than similar tools. Works entirely in the browser so I can use it offline and trust my data stays private.
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Felix K.
2 weeks ago
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The character breakdown table is fantastic for understanding what changed. I use this to teach encoding concepts to my team.
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Nadia R.
3 weeks ago
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Clean, fast, no registration required. The copy button works every time and the stats row gives a great summary.
Encoder Tools📖 How to Use
1
Paste Base64
Paste your Base64 encoded string into the input field.
2
Clean if needed
Click Clean Input if the string has extra whitespace or line breaks.
3
Read the output
The decoded plain text appears in the output field instantly.
4
Format JSON
If the decoded text is JSON, click Try Format as JSON for pretty-printed output.
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❓ FAQ
How do I decode a Base64 string?+
Paste the Base64 string into the input field. The tool automatically decodes it using your browser's atob() function and shows the plain text output instantly.
What if I get an "Invalid Base64" error?+
Common causes: missing padding (= signs), invalid characters (not A–Z, a–z, 0–9, +, /, =), or whitespace within the string. Click Clean Input to remove whitespace, which fixes most errors.
Can this decode URL-safe Base64?+
Yes. URL-safe Base64 uses - instead of + and _ instead of /. This tool automatically converts these back before decoding.
What is Base64 used for in web development?+
Base64 is used in: JWT tokens (header.payload.signature are Base64url encoded), data URIs for embedding images in CSS/HTML, Basic authentication headers, email attachments (MIME), and API responses with binary data.
Can I decode binary data with this tool?+
This tool decodes Base64 to text. Binary files decoded this way may show garbled characters — for proper file decoding you'd need a file download option. Use the clean text output for text-based Base64 data.