How to use the universal converter
- Paste text or an encoded string into the box. Plain text, Base64 values and percent-encoded URLs all fit, and multi-line input is fine.
- Press Encode to Base64 when you have readable text, or Decode automatically when the string already looks encoded. The decoder checks percent escapes first, then Base64, and tells you which format it recognised.
- Copy the result, or use Use result as input to send it back through the converter for a round-trip check.
- Open the Base64 or URL collection below when you need a specialist page: encoding, decoding, JWT and data URL values, or an unknown string that needs format detection.
Browse by theme
The site covers two encoding families. Each collection is led by its most-used tool and links to the smaller specialist pages underneath it.
Theme A · Base64
Base64 Decode
Base64 rewrites bytes as ASCII text. Decode a Base64 value back to words, or encode text before it goes into a data URL, JSON field or API parameter.
Theme B · URL encoding
URL Decode
Percent-encoding makes text safe inside a URL. Decode a link full of %20 escapes, or encode a value before building a query string.
Which tool do I need?
Most visitors arrive knowing what they have but not which tool matches it. This table maps the input in front of you to the page that handles it.
| If you have… | Open this tool | What it does |
|---|---|---|
Text that looks like Base64, such as SGVsbG8= | Base64 Decode | Decodes it back to readable UTF-8 text and explains any failure. |
| Readable text that must become Base64 | Base64 Encode | Encodes text, including Chinese and emoji, with correct UTF-8 handling. |
| A JWT segment, data URL or API payload | Base64 Decoder | Handles the Base64 wrappers developers meet in tokens and payloads. |
| A string with no obvious format | Decode This | Detects Base64 or percent-encoding, decodes it, and names the format it found. |
A URL or query string full of %20 and %E4 | URL Decode | Turns percent escapes back into readable words, including non-ASCII text. |
| Text that must travel safely inside a URL | URL Encode | Percent-encodes spaces, ampersands and non-ASCII characters. |
Base64 or URL encoding: how to choose
Both formats make data safe for channels that only accept text, but they are not interchangeable. Base64 is for moving bytes through a text-only system; URL encoding is for putting text inside the narrow grammar of a URL. A Base64 value pasted into a URL decoder fails, and a percent-encoded string pasted into a Base64 decoder fails too.
| Base64 | URL encoding | |
|---|---|---|
| What it protects | Binary data in text channels | Text inside a URL component |
| What it looks like | SGVsbG8g5LiW55WM | Hello%20%E4%B8%96%E7%95%8C |
| Size change | About 33% larger | Only escaped characters grow |
| Where you meet it | data: URLs, JWT, API payloads, email | Query strings, redirect parameters, form values |
When you are not sure which one you have, Decode This tests the string and tells you which format it recognised instead of returning a guess.
Private by design
Every converter on this site is JavaScript running in the tab. There is no API call behind the buttons and no request carrying your text anywhere, which matters because the values people decode are often customer records, tokens or configuration secrets. You can confirm this in the browser’s network panel: after the page loads, the tools keep working with the network idle, and they keep working offline.
The site is free to use and needs no account. If you want the detail behind that promise, the about page explains how the tools are tested, and the privacy policy covers data handling.
Frequently asked questions
Which tool should I start with?
If you have an encoded string you cannot read, start with Decode automatically above: it checks for percent-encoding, then Base64, and names the format it found. If you have plain text and know the target format, use Base64 Encode for Base64 or the URL Encode page for percent-encoding.
What is the difference between Base64 and URL encoding?
Base64 rewrites binary data as 64 readable characters so it can pass through text-only systems. URL encoding rewrites unsafe characters as %XX escapes so text can sit inside a URL. Neither one is encryption, and neither replaces the other, which is why this site keeps them as separate collections.
Are the tools free, and do I need an account?
All tools are free, with no account, sign-up or usage limit. There is no advertising inside the converter, and nothing you paste is uploaded, stored or logged. The site is funded by its static hosting being inexpensive, not by your data.
What does “Decode automatically” mean?
It means the decoder picks the format for you. A value containing escapes like %20 or %E4 is tried as URL-encoded text first; anything else is tried as Base64. The status line under the buttons always says which decoder succeeded, so you learn what the string was as well as what it says.
Can I use the output commercially, and is it safe to paste sensitive text?
Yes, you can use the output in commercial work. The tools process everything locally, so nothing is sent to a server, but treat any decoded output as untrusted data: a decoded link or script can contain anything. For live secrets, use an offline tool on the machine that owns them and rotate anything that may have leaked.