tesseract.js/examples/file-input/demo.html

<script src="/dist/tesseract.dev.js"></script>
<script>

function progressUpdate(packet){
	var log = document.getElementById('log');

	if(log.firstChild && log.firstChild.status === packet.status){
		if('progress' in packet){
			var progress = log.firstChild.querySelector('progress')
			progress.value = packet.progress
		}
	}else{
		var line = document.createElement('div');
		line.status = packet.status;
		var status = document.createElement('div')
		status.className = 'status'
		status.appendChild(document.createTextNode(packet.status))
		line.appendChild(status)

		if('progress' in packet){
			var progress = document.createElement('progress')
			progress.value = packet.progress
			progress.max = 1
			line.appendChild(progress)
		}


		if(packet.status == 'done'){
			var pre = document.createElement('pre')
			pre.appendChild(document.createTextNode(packet.data.text))
			line.appendChild(pre)
		}

		log.insertBefore(line, log.firstChild)
	}
}

function recognizeFile(file){
	Tesseract.recognize(file)
		.progress(function(packet){
			console.info(packet)
			progressUpdate(packet)

		})
		.then(function(data){
			console.log(data)
			progressUpdate({ status: 'done', data: data })
		})
}
</script>
<input type="file" onchange="recognizeFile(this.files[0])">
<div id="log"></div>


<style>
#log > div {
    color: #313131;
    border-top: 1px solid #dadada;
    padding: 9px;
    display: flex;
}
#log > div:first-child {
    border: 0;
}


.status {
	min-width: 250px;
}
#log {
    border: 1px solid #dadada;
    padding: 10px;
    margin-top: 20px;
    min-height: 100px;
}
body {
    font-family: sans-serif;
    margin: 30px;
}

progress {
    display: block;
    width: 100%;
    transition: opacity 0.5s linear;
}
progress[value="1"] {
    opacity: 0.5;
}
</style>