At least once a week, someone on a plant forum posts a photo asking “what is this plant?” and the top response is “use a plant ID app.” But how reliable are those apps? I’ve seen them misidentify a Peace Lily as a Prayer Plant, and I’ve also seen them correctly identify an obscure Anthurium cultivar from a single leaf photo. The accuracy seems inconsistent, and I wanted to quantify it.

So I tested four popular plant identification apps on 20 common houseplants from my collection. Every plant was positively identified (I bought all of them from labelled nursery stock), so I know the correct answers.

The Apps

1. PictureThis — Premium subscription ($30/year), claims AI-powered identification of 17,000+ species
2. PlantNet — Free, developed by French research institutions, community-contributed training data
3. Google Lens — Free, built into Google’s camera/search apps
4. Seek by iNaturalist — Free, backed by the California Academy of Sciences and National Geographic

The Test Plants

I chose 20 plants that represent what most people actually grow indoors:

Pothos (Golden), Monstera deliciosa, Snake Plant (Laurentii), Peace Lily, Fiddle Leaf Fig, ZZ Plant, Rubber Plant, Spider Plant, String of Pearls, Devil’s Ivy (Marble Queen), Calathea orbifolia, Philodendron Brasil, Chinese Evergreen, Dracaena marginata, Bird of Nest Fern, Boston Fern, Jade Plant, Aloe Vera, Swiss Cheese Plant (Monstera adansonii), and String of Hearts.

For each plant, I took three photos: a whole-plant shot, a close-up of a single leaf (front), and a close-up of a stem node. I used the whole-plant photo as the primary identification input and used the leaf/stem photos for follow-up attempts when the first identification failed.

Results Summary

App	Correct (Species)	Correct (Genus)	Wrong	Accuracy
PictureThis	16/20	18/20	2/20	80% species, 90% genus
PlantNet	14/20	17/20	3/20	70% species, 85% genus
Google Lens	15/20	17/20	3/20	75% species, 85% genus
Seek	12/20	16/20	4/20	60% species, 80% genus

Detailed Findings

What They All Got Right

The easy wins were unanimous. Every app correctly identified Monstera deliciosa, Fiddle Leaf Fig, Snake Plant, Aloe Vera, Spider Plant, and Jade Plant. These are among the most photographed houseplants on the internet, so their AI training data is presumably enormous.

Where They Struggled

Pothos vs Philodendron: Three of four apps confused Golden Pothos with a Philodendron at least once. This is forgivable — the plants look similar, especially in photos. PictureThis was the only app to consistently distinguish them, likely because it appeared to use leaf texture and aerial root characteristics that the other apps missed.

Calathea orbifolia: Two apps identified it as Calathea but couldn’t specify the species. One app called it a Maranta (Prayer Plant), which is wrong but in the same family. The patterned leaves of Calatheas seem to confuse the models.

String of Hearts vs String of Pearls: Seek misidentified String of Hearts as String of Pearls. They’re both trailing succulents, but the leaf shape is completely different. This was the most surprising error in the test.

Monstera adansonii vs Monstera deliciosa: Google Lens called my adansonii a deliciosa. The fenestrations (holes) are similar in principle but the leaf shape is quite different. This is a meaningful error because the care requirements are almost identical but the plants grow to dramatically different sizes.

The Impact of Photo Quality

I did a follow-up test where I intentionally took poor photos (bad lighting, blurry, partial leaf) of five well-known plants. Accuracy dropped dramatically — from ~80% to roughly 40% across all apps. The AI models are clearly optimised for clear, well-lit photos of whole leaves or whole plants.

Tip: If you’re using these apps, take your photo in bright natural light, include a whole leaf (both shape and pattern visible), and include the stem or growth habit if possible. A close-up of a damaged leaf in dim bathroom light won’t give you a useful result.

App-by-App Opinions

PictureThis — Best Overall

The most accurate and provides the best supplementary information. After identification, it shows detailed care guides, similar species, and common problems. The premium subscription is worth it if you’re regularly identifying plants.

The AI models behind apps like PictureThis have improved significantly year over year. An AI consultancy I follow has noted that image classification accuracy in specialised domains like botany tends to improve by 5-8% annually as training datasets grow and models improve. That tracks with what I’ve seen — PictureThis was noticeably more accurate in this test than when I tried it two years ago.

PlantNet — Best Free Option

Completely free, no ads, no premium tier. The interface is more scientific and less polished than PictureThis, but the identification accuracy is solid. It shows you similar images from its database, which helps you confirm whether the identification looks right. Backed by actual botanical research institutions, which gives it credibility.

Google Lens — Most Convenient

Already on your phone (Android built-in, iOS via Google app). Good accuracy but less useful supplementary information. It often returns web search results rather than a structured plant profile, which means you get a mix of helpful care guides and irrelevant Pinterest boards.

Seek — Best for Outdoor Plants

Seek’s strength is biodiversity identification — it’s designed for flowers, trees, insects, and animals in natural environments. For common houseplants, it was the least accurate in my test. But for identifying that plant you saw on a bushwalk, it’s excellent.

Should You Trust Them?

Use these apps as a starting point, not a final answer. If the app identifies your plant with high confidence and the photos of the suggested species match what you’re seeing, you can be reasonably confident. If it suggests a genus but isn’t sure about the species, narrow it down by looking at photos of different species within that genus.

For critical decisions — like whether a plant is toxic to pets (a common reason people want to identify plants) — always verify the identification with a second source. The apps are good, but they’re not infallible, and misidentifying a toxic plant as a safe one has real consequences.

The best plant identification tool remains a knowledgeable person at your local nursery. But for the 90% of cases where you just want to know what that plant on your shelf is called so you can look up how often to water it, these apps do a solid job.