To give you an idea of how accurate Metascraper is, here is a comparison of similar libraries:
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 95.54% | 74.56% | 61.16% | 66.52% | 70.90% |
| Incorrect | 1.79% | 1.79% | 0.89% | 6.70% | 10.27% |
| Missed | 2.68% | 23.67% | 37.95% | 26.34% | 8.95% |
A big part of the reason for Metascraper's higher accuracy is that it relies on a series of fallbacks for each piece of metadata, instead of just looking for the most commonly-used, spec-compliant pieces of metadata, like Open Graph. However, Metascraper is specifically targetted at parsing article information, which is why it's able to be more highly-tuned than the other libraries for that purpose.
Note: this comparison was run against 32 sites and last updated on June 1, 2016. If you're interested, you can check out the full results for each library.
And here is the accuracy of each individual piece of metadata:
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 87.50% | 31.25% | 31.25% | 0.00% | 34.38% |
| Incorrect | 9.38% | 3.13% | 3.13% | 31.25% | 50.00% |
| Missed | 3.13% | 65.63% | 65.63% | 68.75% | 15.63% |
An author is incorrect if it's not in the format of First Last, or has extra junk information in the string.
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 87.50% | 21.86% | 0.00% | 0.00% | 59.38% |
| Incorrect | 0.00% | 3.13% | 0.00% | 0.00% | 18.75% |
| Missed | 12.50% | 75.00% | 100.00% | 100.00% | 15.63% |
A date is correct if it's the correct date, regardless of time. A date is incorrect if it's not in the ISO 8601 format.
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 96.88% | 90.63% | 96.88% | 93.75% | 90.63% |
| Incorrect | 3.13% | 3.13% | 3.13% | 3.13% | 3.13% |
| Missed | 0.00% | 6.25% | 0.00% | 3.13% | 6.25% |
A description is correct if it's either the description the publisher chose, or the first paragraph of the article.
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 100.00% | 100.00% | 100.00% | 100.00% | 100.00% |
| Incorrect | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
| Missed | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
An image is correct if it's either the image the publisher chose, or the first image on the page.
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 96.88% | 81.25% | 0.00% | 78.13% | 81.25% |
| Incorrect | 0.00% | 0.00% | 0.00% | 12.50% | 0.00% |
| Missed | 3.13% | 18.75% | 100.00% | 6.25% | 18.75% |
A publisher is correct if it's the publisher's proper name, or the publisher's domain name.
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 100.00% | 100.00% | 100.00% | 100.00% | 100.00% |
| Incorrect | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
| Missed | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
A title is correct if it's the title of the article, or the title of the page.
| Library | metascraper |
html-metadata |
node-metainspector |
open-graph-scraper |
unfluff |
|---|---|---|---|---|---|
| Correct | 100.00% | 96.88% | 100.00% | 93.75% | 93.75% |
| Incorrect | 0.00% | 3.13% | 0.00% | 0.00% | 0.00% |
| Missed | 0.00% | 0.00% | 0.00% | 6.25% | 6.25% |
A url is correct if it resolves back to the original article.