Entity Extraction: Tools Comparison

Extracting entities from web pages is an essential task for both planning out content and on-page optimization.

Numerous free tools on the market help you achieve this.

In this article, we’ll explore three popular tools that are available for free. We’ll use the same excerpt of content from a Healthline article to compare the quantity and quality of extracted entities.

Let’s check it out.

The Text

Benefits of ZMA supplements

Studies on ZMA’s individual components suggest that the supplement may offer several benefits.
May boost immunity

Zinc, magnesium, and vitamin B6 play key roles in your immune health.

For example, zinc is essential for the development and function of many immune cells. In fact, supplementing with this mineral may reduce your risk of infections and aid wound healing (5Trusted Source, 17Trusted Source, 18Trusted Source).

Meanwhile, magnesium deficiency has been linked to chronic inflammation, which is a key driver of aging and chronic conditions like heart disease and cancer.

Conversely, taking magnesium supplements may reduce markers of inflammation, including C-reactive protein (CRP) and interleukin 6 (IL-6) (19Trusted Source, 20Trusted Source, 21Trusted Source).

Lastly, vitamin B6 deficiency has been linked to poor immunity. Your immune system requires vitamin B6 to produce bacteria-fighting white blood cells, and it enhances their ability to combat infection and inflammation (22Trusted Source, 23Trusted Source, 24Trusted Source).
May aid blood sugar control

Zinc and magnesium may help people with diabetes control their blood sugar levels.

An analysis of 25 studies in over 1,360 people with diabetes showed that taking a zinc supplement reduced fasting blood sugar, hemoglobin A1c (HbA1c), and post-meal blood sugar levels (6Trusted Source).

In fact, it found that supplementing with zinc lowered HbA1c — a marker for long-term blood sugar levels — to an extent similar to that of metformin, a popular diabetes drug (6Trusted Source, 25Trusted Source).

Magnesium may also improve blood sugar control in people with diabetes by improving the body’s ability to use insulin, a hormone that moves sugar from your blood into cells (26Trusted Source).

In fact, in an analysis of 18 studies, magnesium was more effective at reducing fasting blood sugar levels than a placebo in people with diabetes. It also significantly reduced blood sugar levels in those at risk of developing diabetes (27Trusted Source).
May help improve your sleep

The combination of zinc and magnesium may improve your sleep quality.

Research suggests that magnesium helps activate the parasympathetic nervous system, which is responsible for helping your body feel calm and relaxed (28Trusted Source, 29Trusted Source).

Meanwhile, supplementing with zinc has been linked to improved sleep quality in both human and animal studies (30Trusted Source, 31Trusted Source, 32Trusted Source).


The Tools

ToolNumber of EntitiesQuality rating (out of 5)
Google Natural Language Demo1294
IBM Watson NLU Demo201


OpenAI’s ChatGPT returned the fewest total entities. However, the results look extremely useful for a quick overview.

  • ZMA supplements
  • Zinc
  • Magnesium
  • Vitamin B6
  • Immune health
  • Immune cells
  • Inflammation
  • C-reactive protein (CRP)
  • Interleukin 6 (IL-6)
  • Blood sugar control
  • Diabetes
  • Fasting blood sugar
  • Hemoglobin A1c (HbA1c)
  • Post-meal blood sugar levels
  • Metformin
  • Sleep quality
  • Parasympathetic nervous system

Google Natural Language Demo

Google’s tool returned a vast amount of entities compared to the others. However, there were several duplicates e.g. ‘zinc’ and ‘Zinc’, which affected the total number of results.

The tool also returned a few bogus results, such as:

  • 19Trusted Source
  • 27Trusted Source
  • 17Trusted Source

This would happen through classification rather than these entities coming from the knowledge graph. Numbers are considered entities, and since the pasted text had some formatting issues, this is what happens.

Another helpful feature of the demo is that it offers a salience score, which is a score to help you understand the prominence/importance of the entity to the page.

IBM Watson NLU Demo

IBM Watson’s Natural Language Understanding tool is extremely useful for many things, including content categorization. However, when it comes to entity extraction, it often fails to deliver. Of the 20 results the tool provided, the majority were number entities.

ChatGPT Vs. Google: Entity Extraction

The two tools that showed the best results were ChatGPT and Google’s Natural Language Demo. So let’s dive a little deeper into them both.

Google’s tool returned 129 total entity results, so ChatGPT missed a lot. However, did Google’s tool miss any that ChatGPT didn’t?

Yes, some.

  • Immune Health
  • Immune Cells
  • C-reactive protein (CRP)
  • Interleukin 6 (IL-6)
  • Post-meal blood sugar levels

However, are all of these entities?

Not quite.

For example, ‘post-meal blood sugar levels’ would be considered not an entity, while ‘blood sugar levels’ are considered an entity with the type ‘other.’

You can see in the image below that Google understands that when given some of these words in isolation.

It breaks those ‘missing entities’ into individual entities. This means that ChatGPT has a margin of error for entity extraction for reasons unknown.

Google’s tool:

  • Google provides far more results. However, many of them aren’t particularly useful.
  • The measure of salience allows you to focus on the most prominent entities.
  • Often returns duplicates because of how NER (Named Entity Recognition) works.


  • ChatGPT provides a smaller, very relevant list of entities that can be useful for efficient sorting.
  • Some of the results may not be actual entities.


While this was a fun little experiment, and it was helpful to discover that ChatGPT’s results aren’t always providing actual entities, it’s still left us with an obvious conclusion. There are no perfect tools for these tasks at present, and it will continue to be somewhat time-consuming.

That said, Google’s demo is only a demo. Upgrading to the paid API would allow you to filter results, making the task much more manageable, especially since the clear winner here is Google’s tool, which makes a lot of sense when you want to work with these for SEO.