You can install a web browser that supports at least JavaScript 1.0 (1995) to use this tool or you may consider implementing a Web0/gemiweb browser with JavaScript0 yourself according to the following specification:
https://bkil.gitlab.io/gemiweb0
javascript: URI
Support
DOM0 NS2
document.cookie
Support
DOM0 NS2
document.write
Support
DOM0 NS2
window.location.href
Support
DOM0 NS2
setInterval
Support
DOM0+ NS4
Document.createElement
Support
DOM1 IE5 NS6
stytle.cssText
Support
DOM2
addEventListener
Support
DOM2
XPathEvaluator createExpression
Support
DOM3
String indexOf
Support
JS1 NS2
Special result
-1
String toUpperCase
Support
JS1 NS2
Special result
none
String substring
Support
JS1 NS2
Special result
''
String charAt
Support
JS1 NS2
Special result
''
parseInt
Support
JS1 NS2
Special result
NaN
setTimeout
Support
JS1 NS2
for-in
Support
JS1 NS2
Special result
none
eval
Support
JS1 NS2
Special result
throw, undefined
Date.parse
Support
JS1 NS2
Special result
NaN
Date toJSON
Support
ES5
Special result
null, throw
Math.min
Support
JS1 NS2
Special result
Infinity, NaN
object reference cycles
Support
JS1 NS2
>>>
Support
JS1 NS2
Special result
none
,
Support
JS1 NS2
Special result
none
isNaN
Support
JS1 NS2
Special result
none
?:
Support
JS1 NS2
Special result
none
escape
Support
JS1 NS2 (ES1 browser)
Special result
none
unescape
Support
JS1 NS2 (ES1 browser)
Special result
none
String charCodeAt
Support
ES1
Special result
NaN
String.fromCharCode
Support
ES1
Special result
none
String split
Support
ES1
Special result
[], [''], throw
Array join
Support
ES1
Special result
none
Array reverse
Support
ES1
Special result
none
Array sort
Support
ES1
Special result
throw
Function
Support
ES1
Special result
throw
Number toString(radix)
Support
ES1
Special result
throw
String substr
Support
ES3 browser
Special result
''
Array concat
Support
ES3
Special result
none
Array push
Support
ES3
Special result
none
Array pop
Support
ES3
Special result
undefined
Array shift
Support
ES3
Special result
undefined
Array unshift
Support
ES3
Special result
none
Array splice
Support
ES3
Special result
[]
Array slice
Support
ES3
Special result
[]
Object hasOwnProperty
Support
ES3
Special result
none
String slice
Support
ES3
Special result
''
String localeCompare
Support
ES3
Special result
-0, 0
String match
Support
ES3
Special result
null, throw
String replace
Support
ES3
Special result
throw
String search
Support
ES3
Special result
-1, throw
function(){}
Support
ES3
[]
Support
ES3
{a:9}
Support
ES3
encodeURI
Support
ES3
Special result
throw
decodeURI
Support
ES3
Special result
throw
===
Support
ES3
instanceOf
Support
ES3
Special result
throw
throw
Support
ES3
do-while
Support
ES3
switch-case-default
Support
ES3
use strict
Support
ES5
Array.isArray
Support
ES5
Special result
none
Array every
Support
ES5
Special result
throw
Array filter
Support
ES5
Special result
throw
Array map
Support
ES5
Special result
throw
Array reduce
Support
ES5
Special result
throw
Array some
Support
ES5
Special result
throw
Array forEach
Support
ES5
Special result
throw
Object.defineProperty
Support
ES5
Special result
throw
Object.freeze
Support
ES5
Object.keys
Support
ES5
Special result
throw
String trim
Support
ES5
Special result
none
JSON.parse
Support
ES5
Special result
throw
JSON.stringify
Support
ES5
Special result
null, throw, undefined
[9,]
Support
ES5
{x:9,}
Support
ES5
const
Support
ES6
let
Support
ES6
Array from
Support
ES6
set Object __proto__
Support
ES6 browser
Special result
throw, undefined
ArrayBuffer slice
Support
ES6
Special result
throw
DataView getUint8
Support
ES6
Special result
throw
Generator
Support
ES6
Promise.race
Support
ES6
Reflect.construct
Support
ES6
Special result
throw
Proxy.revocable
Support
ES6
Special result
throw
import
Support
ES6
=>
Support
ES6
[x]=[9]
Support
ES6
Special result
throw
String.raw
Support
ES6
Uint8Array.from
Support
ES6
Special result
throw
WeakMap set
Support
ES6
Special result
throw
Symbol.keyFor
Support
ES6
Special result
throw, undefined
super
Support
ES6
`${x}`
Support
ES6
[...[1,2]]
Support
ES6
Special result
throw
for-of
Support
ES6
Special result
throw
??
Support
ES7
?.
Support
ES11