Encoding & conversion
Move data between the representations it travels in, without losing anything on the way.
Data rarely moves in the form you wrote it. Bytes become Base64 so they survive a text-only channel; spaces and ampersands become percent escapes so a URL stays one URL; a date becomes a count of seconds so it sorts and compares cheaply. Each of those conversions is reversible, and each one is the source of a particular category of bug when it is applied twice, or not at all.
These three tools do the conversion both ways and show you the result as you type, so you can tell double-encoding from single-encoding by looking at it. All of them run entirely in your browser: the text, the file and the timestamp stay on your device.
3 tools in encoding & conversion
Convert epoch timestamps to readable dates and back, with the unit detected automatically and a live clock.
Try nowPercent-encode and decode URLs, and read any query string as a plain, already-decoded table.
Try nowEncode and decode Base64 — UTF-8 text, data URIs, and Base64 back into a PDF, image or file you can download.
Try nowWhich one do you need?
- A URL breaks when it contains a space, a plus or an ampersand
- The URL encoder shows both encodeURIComponent and encodeURI output side by side, and reads any query string back as a table of already-decoded parameters — which is how you spot a value that was encoded twice.
- You have a blob of letters ending in = or ==
- That is almost certainly Base64. The Base64 decoder turns it back into UTF-8 text, and handles the URL-safe alphabet as well as files and data URIs.
- A log line has a ten- or thirteen-digit number where a date should be
- The timestamp converter detects whether it is seconds, milliseconds or microseconds for you, and gives the date in ISO 8601, UTC, your local time and relative form.
Guides for these tools
Frequently asked questions
Is Base64 a form of encryption?
No, and this is the most expensive misunderstanding in the list. Base64 is a reversible encoding with no key — anyone who has the string has the data. It exists to move binary safely through text channels, not to hide anything. Never use it to protect a secret.
Why does my encoded string keep growing?
Because you are encoding something already encoded. Percent-encoding turns % into %25 and Base64 adds about a third to the length each pass, so applying either twice is visible immediately — decode once and check whether you get plain text or another encoded string.
Do these tools work on files as well as text?
The Base64 tool does — drop a file in and it produces a data URI you can paste straight into CSS or an img tag. The URL and timestamp tools are text-only.