Base64 Encoder Decoder Online

Encode plain text to Base64 or decode Base64 back to text. Supports standard and URL-safe (RFC 4648) encoding.

Plain Text
Base64 Output
Encoded Base64 will appear here…
💡

Quick Answer

Base64 encoding converts text or binary data into a string of 64 printable ASCII characters — making it safe to transmit across text-based protocols like HTTP and email.

What is Base64 Encoding?

A Base64 encoder decoder online is a free tool that converts text to Base64 and back instantly. Whether you need to encode data for API requests, decode Base64 blobs from webhooks, or embed files as data URIs — this free Base64 tool handles it all directly in your browser with no installation required.

Encode Example

InputHello, NexoraTools!
Base64 OutputSGVsbG8sIE5leG9yYVRvb2xzIQ==

Decode Example

Base64 InputTmV4b3JhVG9vbHM=
Decoded OutputNexoraTools

Standard vs URL-safe Base64

Standard Base64 uses + and / characters which have special meaning in URLs. URL-safe Base64 (RFC 4648) replaces these with - and _ so the encoded value can be embedded directly in query strings, path parameters, and HTTP headers.

Standard Base64

SGVsbG8+V29ybGQ=

Uses + and / — not safe in URLs without percent-encoding.

URL-safe Base64

SGVsbG8-V29ybGQ=

Replaces + with - and / with _ — safe in query strings and headers.

What is Base64 Encoder Decoder Online?

A Base64 encoder decoder online is a browser-based tool that converts text and binary data to Base64 encoding and back. It supports standard and URL-safe modes (RFC 4648), handles Unicode correctly via TextEncoder, and processes everything locally with no server calls.

Key Features

Encode & decode textConvert plain text to Base64 or reverse Base64 back to readable text instantly
URL-safe modeToggle RFC 4648 URL-safe encoding with - and _ substitutions
Unicode supportCorrectly handles multi-byte UTF-8 characters including emoji and CJK scripts
Swap input/outputOne-click swap to reverse the direction for quick round-trip testing
Real-time conversionOutput updates immediately as you type — no manual submit required
100% client-sideAll encoding and decoding happens in your browser — data never leaves your device

Common Use Cases

API Development

Encode request payloads for multipart APIs, decode Base64 response fields, or inspect JWT payloads during development.

HTTP Authentication

Basic Auth sends credentials as Base64-encoded username:password — decode intercepted headers to inspect them.

Data URLs

Embed images, fonts, or small files directly into HTML and CSS as Base64 data URIs without separate HTTP requests.

Email Systems

MIME email encodes binary attachments in Base64 to safely transmit them over text-only SMTP protocols.

Environment Secrets

Store binary secrets, certificates, or keys as Base64 strings in environment variables and configuration files.

Debugging

Decode Base64 blobs received from third-party APIs or webhooks to inspect the underlying data during development.

Why Use This Tool

  • Handles Unicode correctlyUses TextEncoder for proper UTF-8 byte encoding — prevents garbled output for non-ASCII characters.
  • Both modes in one toolSwitch between standard and URL-safe Base64 without opening a second tool.
  • No backend dependencyEncode sensitive credentials or secrets without sending data to any external server.
  • Instant round-trip testingEncode a value and immediately decode it to verify the output is correct.
  • Always freeNo rate limits, no sign-up, no ads — available instantly from any browser.

Frequently Asked Questions

What is Base64 encoding used for?

Base64 encoding converts binary or text data into a string of 64 printable ASCII characters — used in API payloads, data URIs, MIME email, and HTTP Basic Auth to safely transmit data over text-only channels.

How do I encode text to Base64?

Paste your text into the input panel and select Encode. The tool instantly converts it to Base64 using standard or URL-safe encoding, depending on your selection.

What is URL-safe Base64?

URL-safe Base64 (RFC 4648) replaces the + and / characters with - and _ so the encoded value can be used directly in URLs without percent-encoding.

Does Base64 encrypt my data?

No. Base64 is encoding, not encryption. Anyone can decode a Base64 string — do not use it to protect sensitive data without additional encryption.

Is this Base64 tool free to use?

Yes. The Base64 Encoder / Decoder on NexoraTools is completely free and processes all data locally in your browser.

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