Percent-encode a string for use in a URL, or decode one.
How to use this calculator
Every field updates the result as you type — there is no submit step. The inputs below are pre-filled with a realistic example so you can see how the tool behaves before entering your own figures.
| Field | Unit | What it means |
|---|---|---|
| Mode | — | Select the mode that matches your situation. |
| Input | — | Enter one entry per line, or separate values with commas. |
| Encode as a component (encodes & = ? #) | yes / no | Toggle this on to include it in the calculation. |
Worked example
Using the default values loaded into the calculator above, the result is:
| Input | Value |
|---|---|
| Mode | Encode |
| Input | search query?a=1&b=two three |
| Encode as a component (encodes & = ? #) | yes |
| Output | Value |
|---|---|
| Encoded | search%20query%3Fa%3D1%26b%3Dtwo%20three |
| Input length | 28 |
| Output length | 40 |
| Characters escaped | 6 |
Reading the result
Conversion factors and physical constants used here are the standard published values. Where a result depends on a material property, local code or regional convention, that value is exposed as an input so you can match it to your situation.
For construction and electrical work, always verify against the codes that apply in your jurisdiction.
Sharing and saving a calculation
The "Copy link" button encodes every value you have entered into the page URL. Opening that link restores the calculation exactly, which makes it easy to bookmark a scenario, send it to someone else, or keep several variations side by side in separate tabs.
Frequently asked questions
What does the URL Encode / Decode do?
Percent-encode a string for use in a URL, or decode one.
What result do the default values produce?
With the values pre-loaded in the calculator, encoded comes to search%20query%3Fa%3D1%26b%3Dtwo%20three.
Is this calculator free to use?
Yes. It is free, requires no account, and runs entirely in your browser — nothing you enter is transmitted or stored on a server.
Can I save or share a calculation?
Yes. The "Copy link" button builds a URL containing all your entered values. Anyone opening that link sees the same calculation.
How accurate is the result?
The calculation itself is exact for the inputs given. Real-world accuracy depends on how well those inputs reflect your actual situation, so review the assumptions before relying on the figure.