Highcharts tooltip overflow is hidden

This css helped me:

.highcharts-container { overflow: visible !important; }

OK, sorry for the delay. I could not find a better solution, but I found a workaround.

Here is what I did and what I suggest everyone to try:

Set the tooltip.useHTML property to true (now you can have more control with html and CSS). Like this:

tooltip: {    useHTML: true    }

Unset all the default tooltip peoperties that may have something to do with the default tooltip functionalities. Here is what I did...

tooltip: {                            shared: false,    borderRadius: 0,    borderWidth: 0,    shadow: false,    enabled: true,    backgroundColor: 'none'}

Make sure that your chart container's css property "overflow" is set to visible. Also make sure that all DOM elements (div, section, etc....) that hold your chart container also have the css "overflow" property set to "visible". In this way you will make sure that your tooltip will be visibile at all times as it overflows his parent and his other "ancestors" (Is this a correct term? :)).

Customize your tooltip formatter as you wish, using standard CSS styling. Here is what I did:

tooltip.formatter: {    < div class ="tooltipContainer"> Tooltip content here < /div >}

This is how it all looks like:

tooltip: {                            tooltip.formatter: {        < div class ="tooltipContainer"> Tooltip content here < /div >    },    useHTML: true,    shared: false,    borderRadius: 0,    borderWidth: 0,    shadow: false,    enabled: true,    backgroundColor: 'none'}

If you have a better solution, please post.

A modern approach (Highcharts 6.1.1 and newer) is to simply use tooltip.outside (API):

Whether to allow the tooltip to render outside the chart's SVG element box. By default (false), the tooltip is rendered within the chart's SVG element, which results in the tooltip being aligned inside the chart area. For small charts, this may result in clipping or overlapping. When true, a separate SVG element is created and overlaid on the page, allowing the tooltip to be aligned inside the page itself.

Quite simply this means setting this one value to true, for example:

Highcharts.chart('container', {    // Your options...    tooltip: {        outside: true    }});

See this JSFiddle demonstration of how setting this value to true fixes space/clipping issues.