Testing Plant Identification Apps – Which Is Best?

Ok, so I like using plant identification apps as they can be a quick way to get a hint, or even identify species of flowers, vines, or trees. But can you trust them? I wanted to answer that question. So, I decided to grab the most popular apps on the App Store based on downloads and ratings, and then put a series of images through each of them.

Note – since each of these apps will likely be updated periodically, this data should only be considered current as of 24MAY2024.

I’m going to save you the time of reading this article though – the results showed that PictureThis and Plant.net performed the best consistently in each plant category. After testing each App with 234 images, PictureThis was the best plant identification app with correct identifications 78% of the time, and Plant.net was the second best plant identification app, being correct 68% of the time. This was above the other five apps I tried. I really spent a long time doing this test, as with most of the apps you have to sit there and upload image after image after image after image…….ugh.

However, I have to offer this disclaimer upfront – I’m trying to test the accuracy of these apps based on a series of pictures where I already know the ID. I am not relying on these apps to identify plants for me. An app should not be your sole source of information as to the identity of a plant, and you should never rely on an app for foraging or to determine whether or not something is safe to eat. Do your own research, and you are responsible for your own actions.

Plant ID apps that were tested

Plant Story	Downloads	Average Rating	# Ratings
PlantAPP	1M	4.6	297k
PlantIN	5M	4.3	95k
PlantNet	10M	4.4	234k
PictureThis	50M	4.6	559k
Blossom	5M	4.6	177k
Lens	1B	4.6	2M
Inaturalist	1M	4.0	9k

Criteria

All in all I tested seven apps by uploading 234 images to each app, one at a time. These were images of plants I was certain of the ID, and thus would record the results based on what the App told me. The grading for each answer was as follows in the table below:

Answer	Criteria
Correct	The app listed the correct species as it’s only, or first answer
Partially Correct	The app suggested several species, of which one was correct. Or, it suggested the correct genus.
Incorrect	The app either said it could not identify the image, or gave an incorrect identification.

Methodology

I went into my archives and retrieved images for a wide variety of trees, flowers, grasses, and vines. In total I gathered 234 images covering nearly 80 species. I then put each image through each identification app, one at a time, recording if the app correctly identified the image or not.

Even though some of the apps have the ability to have multiple images uploaded (Blossom, Inaturalist, Plant.net), I only uploaded images one at a time to make sure each app had the same information with each identification request. This test took a really long time!

Example images

Below is a sample gallery of images uploaded.

Results

Overall, PictureThis had the highest accuracy rating of all apps. If one were to include partial correct images, then it would essentially be tied with Plant.net. Inaturalist also scored very high, although it had few ‘correct’ ID’s but many ‘partially correct’. I believe this to be due to Inaturalist being the most conservative in identification – it almost never makes confirmed ‘ID’ unless it is very certain.

One surprising finding was that many apps were quite good at differentiating milkweeds. And almost every app could identify Japanese Stilt Grass from at least one of the four images tested (even it in the seedling stage).

But below you will find a table of raw results, along with a series of charts you can examine showing each app’s accuracy. Picture this was clearly the best for correct identifications. If one combines both correct identifications and partial (because most apps are conservative), then PictureThis and Plant.net were essentially equal at approximately 80%.

APP	Correct ID	Partial ID	Incorrect ID
Plant Story	44%	27%	29%
Plant App	57%	3%	40%
PlantNet	68%	13%	19%
PictureThis	78%	0%	21%
inaturalist	39%	41%	19%
Blossom	40%	8%	52%
Lens	48%	4%	36%

Below is a small gallery showing results sorted in different categories;

One interesting result though was that most apps could identify, or at least get close to identifying trees based on bark. While others seemed to be more specialized at ornamental flowers. Again, even though there were differences between the apps based on plant type, overall PictureThis and Plant.net seemed to outperform the others.

Video review / test

So, I made a YouTube video documenting my testing of these apps. It gives you all the same info you have in this article, but offers some more commentary. Hope you enjoy it!

Discussion

This was a fun experiment. But consideration needs to be taken when using plant identification apps. The most accurate app, PictureThis, generally only offers a single suggestion for each identification. As long as it is accurate, this is fine. But it isn’t hard to imagine a scenario where an app could misidentify a plant that was poisonous to people or pets. So, based on that, I personally prefer using Plant.net in addition to PictureThis, as it generally offers multiple suggestions, which I prefer. But, do your own research, you are responsible for your own actions.

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