What this site is
EncodeKit is organised around two themes, each with its own collection. The Base64 collection is led by Base64 Decode, which decodes Base64 back into readable text, and includes the encoder, the developer decoder and Decode This for unknown strings. The URL collection is led by URL Decode and pairs it with URL Encode for percent-encoding values before they go into a link. The home page is the total entry point: a universal converter plus links to both collections.
The site is plain HTML, CSS and JavaScript. There is no framework, no build step, no database and no CDN. That is a deliberate choice: every tool runs from files that could be served from a USB stick, and the only thing the browser has to load is the page itself. It also means the conversion code is small enough to read, if you want to check what it does.
How the tools are tested
Each tool is checked by hand before it ships, because an encoding tool that is subtly wrong is worse than one that does not exist. The current test set covers:
- Round trips with mixed text: ASCII, Chinese, Japanese, Arabic, accented Latin, emoji and control characters, encoded and then decoded to confirm the output is byte-for-byte identical to the input.
- Malformed input: illegal Base64 characters, impossible lengths, missing padding, binary payloads, incomplete percent escapes and invalid UTF-8 byte sequences. Each one must produce a readable explanation rather than a silent wrong answer.
- Real-world formats: JWT header and payload segments, data: URLs, MIME Base64 wrapped at 76 characters, URL-safe Base64, query strings and double-encoded redirects.
- Multiple browsers: Chrome, Edge, Firefox and Safari on desktop, plus the mobile browsers on iOS and Android, because the encoding APIs used here are standard but the clipboard and textarea behaviour are not identical.
- Network behaviour: with the page loaded, the converters must work with the network panel showing no requests, since all processing happens locally.
Editorial standards and corrections
Every page shows the date it was last reviewed. The explanations reference the standards they describe — RFC 4648 for Base64 and RFC 3986 for percent-encoding — so a reader can verify a claim instead of taking it on faith. The command-line tables are checked on current PowerShell, macOS and Linux releases; when a tool changes its flags, the page changes with it.
When something is wrong, it is corrected on the page rather than noted in a hidden changelog, and the review date moves with the correction. If you find an error, a broken example or a case the decoder handles badly, email us with the page address and the exact input; that report is the most useful contribution a reader can make.
Why the tools are free
The site is cheap to run because it is a set of static files with no server-side processing. That cost is low enough that the tools can stay free, with no account, no paywall and no advertising inside the converter. If that ever changes, the change will be visible and separate from the tool itself: no codes or ads inside the input and output areas, and no feature removed from a page you already use.
There is also no plan to sell your data, because there is no data to sell. The text you paste is processed in the tab and never sent anywhere. That is both a privacy position and an engineering one: a static site has nowhere to put it.
How to reach us
Email [email protected] for corrections, bug reports, permission questions or suggestions for a tool that fits the encoding theme. A useful report includes the page address, your browser and version, the exact input, and what you expected to see instead.
The site is written and maintained by the EncodeKit team, a small independent group of web developers who use these encoders in their day-to-day work. There is no company behind it to route a message through, which is why email is the fastest way to reach a person who can actually fix the thing you found.
Frequently asked questions
Who writes and maintains EncodeKit?
The site is maintained by the EncodeKit team, an independent group of web developers. The tools are built with standard browser APIs, the explanations are based on the RFC standards they cite, and every page carries a visible review date so you can see when it was last checked.
Can I use these tools for commercial work?
Yes. There is no licence fee and no usage limit for the output. You can use the tools for client work, internal tooling or documentation. The site's text, design and code remain the property of EncodeKit and should not be republished as another site.
How do I report a bug or request a new tool?
Email [email protected] with the page address, your browser and version, the exact input that caused the problem and what you expected to happen. Bug reports with a reproducible input are usually fixed fastest. New tools are considered when they fit the encoding theme, such as other character sets or developer encodings.