Instagram hides the number of Likes in Posts in several countries, including Australia and Japan, to "eliminate" the pressure on users.
The trial version that starts on Thursday means users will see a username "and others" in their feed below the posts instead of the number.
Instagrammers can still see the number of likes they get their own posts.
There are concerns that social media platforms can contribute to low self-esteem and inadequacy among young people.
Instagram launched a similar study in Canada in May and the new test will be launched in Australia, New Zealand and Ireland, Italy, Japan and Brazil, the BBC company said.
"We hope that this test removes the pressure on how many Likes a post will receive, so you can focus on sharing the things you love," said Mia Garlick, Director of Policy Facebook Australia and New Zealand in a statement.
The goal, she adds, is that users feel less judged and see "whether this change will help people focus less on preferences and more on storytelling."
Instagram said the test would not affect the measuring instruments for companies. And users can continue to view the list of people who like others' content by clicking on it.
When the test was first conducted in Canada, the Instagram boss Adam Mosseri said the goal was to minimize the stress of online posting while users around the number of likes that get their posts compete.
"We want people to think a little less about how many people find them on Instagram, and spend a little more time connecting with the people they care about," he said currently.
The number of likes received is a measure of success or popularity on Instagram.
Studies suggest that this type of instant feedback on content may enhance people's self-esteem, but may affect others if they do not get that many likes.
Studies have linked social media platforms to mental health effects, especially for young people.
The number of likes is also the way to rate a post for Instagram's business page.
Influencers paid for the content they post in their posts are measured by the number of likes their social media activity draws.
Earlier this month, Instagram also unveiled a new feature to combat online bullying.