Base64 Encoder / Decoder - Encode, Decode & Convert Base64URL Online
Free online Base64 encoder and decoder with Base64URL support. Encode UTF-8 text, decode Base64 payloads, inspect padding and validity, and convert data entirely in your browser.
Conversion Workspace
Encoded Result
Jump into realistic payloads
Where this helps
- Inspect encoded API values and webhook fields
- Generate URL-safe payloads for browser redirects
- Decode copied config blobs and token segments
- Check whether decoded output is readable JSON
Local-only conversion
OpsKit performs all Base64 and Base64URL conversion in your browser using native web APIs. No request is sent to a server when you encode or decode content.
What is Base64?#
Base64 is a text-based encoding format that converts binary or UTF-8 text into a limited set of ASCII characters. It is commonly used when data needs to travel through systems that safely handle text but not raw bytes.
You will frequently see Base64 in:
- API payloads and auth flows
- email MIME bodies and attachments
- data URLs and inline assets
- JSON configuration exports
- tokens, certificates, and integration tooling
Base64 is encoding, not encryption. Anyone can decode it if they have the payload.
How to Use This Base64 Tool#
- Choose whether you want to Encode or Decode.
- Select the format: Base64 or Base64URL.
- Paste input into the editor.
- Copy the result, swap direction, or load a different sample.
The page updates instantly and never sends your data to a backend service.
Base64 vs Base64URL#
Both formats represent the same underlying idea, but they use slightly different character sets.
| Format | Character set | Typical use case |
|---|---|---|
| Base64 | Uses +, /, and optional = padding | General encoding, MIME, files, config data |
| Base64URL | Uses -, _, and often omits padding | URLs, JWT segments, query params, browser-safe tokens |
If you are working with JWTs or URL parameters, Base64URL is usually the safer choice.
Why Use an Online Base64 Encoder / Decoder?#
Debug API and Integration Payloads#
Inspect encoded request values, copied webhook fields, or opaque config blobs without leaving the browser.
Convert Text for URLs and Tokens#
Generate URL-safe Base64 values for browser redirects, signed links, and lightweight integration testing.
Validate Suspicious Payloads Quickly#
See whether a string is actually valid Base64, whether padding is missing, and whether decoded output looks like JSON.
Stay Private While Working#
This page performs conversion entirely on your device. Nothing is uploaded or stored remotely.
Privacy & Security Notes#
- 100% client-side: conversion happens locally in your browser.
- No storage: the tool does not persist your input to a backend.
- Not encryption: do not mistake Base64 for security or secrecy.
- Use care with sensitive data: even though the tool is local-first, avoid exposing production secrets in screenshots, recordings, or shared sessions.
FAQ#
Is this Base64 tool free?#
Yes. It is free to use and works directly in your browser.
Does the tool support UTF-8 text?#
Yes. It safely handles UTF-8 input and output, so regular text, symbols, and multilingual content encode correctly.
What happens if my Base64 string is invalid?#
The page shows a readable error state instead of returning broken output. It also helps identify missing padding and malformed characters.
What is Base64URL?#
Base64URL is a URL-safe variant of Base64 that replaces + with -, / with _, and commonly removes trailing = padding.
Can I use this to decode JWT payload segments?#
Yes, for inspection and debugging. JWT segments are typically Base64URL-encoded. If you need a full token workflow, use JWT Tools.
Related Tools#
- JWT Tools - Decode and analyze JWT segments and claims
- JSON Beautifier - Format decoded JSON payloads for readability
- JSON Linter - Validate JSON after decoding Base64 data
- YAML/JSON Path Tester - Query decoded JSON structures