Base64 Decode & Encode — Free, No Signup

Decode Base64 strings to text or encode text and files to Base64 instantly. 100% browser-based — your data never leaves your device.

Decode & encode Browser-only — 100% private Image preview Works on mobile
✅ 100% Free 🔒 SSL Secured ⚡ Instant 🗑️ Files Deleted in 1hr

🔒 SSL encrypted · 100% browser-based — data never leaves your device · Works on Windows, Mac, Linux, Android & iPhone

Text Input 0 chars
No file chosen
Base64 Output 0 chars
Decoded image preview
100% browser-only — data never leaves your device Instant results Any file type supported
more about this tool
How it works

How to decode or encode Base64 online — instantly

Everything happens in your browser. No data is sent to any server — ever. Works on Windows, Mac, Linux, Android and iPhone.

  1. 1Choose mode — click Decode ← Base64 to convert a Base64 string to text, or Encode → Base64 to convert text or a file to Base64.
  2. 2Paste or upload — paste your text or Base64 string into the input area, or click Upload File to load any file directly.
  3. 3Click Convert — the result appears instantly in the output area. Copy to clipboard, download as .txt, or view an image preview if you decoded a Base64 image.
Use cases

What Base64 decode and encode is used for

Base64 is one of the most common encoding formats in web development, APIs and data transfer.

  • →Decode Base64 string online free — decode Base64 API responses, JWT tokens and data URIs from web applications to readable text
  • →Base64 decoder for developers — quickly inspect Base64 payloads in API calls, HTTP headers, email attachments and JSON Web Tokens
  • →Encode image to Base64 for CSS — convert images to Base64 data URIs to embed directly in CSS or HTML without a separate file request
  • →Decode Base64 image — paste a Base64 image string and preview the decoded image directly in your browser before using it
  • →Base64 encode file — encode any file to Base64 for safe transmission over text-based protocols like SMTP email and REST APIs
  • →Decode Base64 credentials — safely decode Basic Auth credentials and other Base64-encoded strings during API development and debugging
  • →Base64 decode free for developers India — decode JWT tokens, API keys and Base64 payloads — including Aadhaar DigiLocker API responses and government portal tokens
  • →Base64 for MIME email attachments — encode binary attachments to Base64 for inclusion in MIME-formatted email messages
What users say

Trusted by developers, students and system integrators

★★★★★

"I debug API payloads every day and always need a quick Base64 decoder. This is the cleanest one I've found — browser-only, no login, and the image preview for data URIs is genuinely useful."

— Shreyas P., Bengaluru · Backend developer
★★★★★

"I use the encode mode to prepare images for CSS data URIs. The fact that nothing gets sent to a server matters for work projects. Fast, private and free — exactly what I needed."

— Priya K., Mumbai · Frontend developer
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FAQ

Frequently asked questions

Everything you need to know about Base64 decoding and encoding online free.

Select Decode from Base64 mode, paste your Base64 string into the input area, and click Convert. The decoded text appears instantly — copy to clipboard or download as a .txt file. No signup, completely free, browser-only.
Select Encode to Base64 mode, paste your text into the input area, and click Convert. The Base64-encoded string appears instantly in the output — ready to copy or download.
Yes. Click Upload File in encode mode and select any file. The file is converted to a Base64 string instantly in your browser — no upload to any server.
Yes — completely private. Zappy Tools Base64 decoder and encoder works entirely in your browser using JavaScript. Your text and files are never sent to any server, never stored, and never logged.
Yes. Paste a Base64 image string — with or without the data:image/png;base64, prefix — and click Decode. If the decoded output is a valid image, a preview appears automatically below the output area.
Base64 is used to encode binary data as ASCII text — common in email attachments (MIME), embedding images in CSS or HTML as data URIs, API tokens, JSON Web Tokens (JWT) and transmitting binary data over text-based protocols.
Encoding converts plain text or binary data to a Base64 string — making it safe to transmit over text-based systems. Decoding reverses this — converting a Base64 string back to its original text or binary content.
Yes. Works on Android and iPhone browsers — no app download required. Paste or type your input and get instant results.