Merlin Bird ID is a world-class AI-powered nature and science application designed to identify bird species through real-time audio and visual analysis.
Introduction
Merlin Bird ID is a world-class AI-powered nature and science application designed to identify bird species through real-time audio and visual analysis.
Developed by the Cornell Lab of Ornithology, the app leverages a massive database of millions of photos and recordings from the eBird citizen-science project. Merlin uses advanced machine learning algorithms to process “Sound ID” (spectrogram analysis of birdsong) and “Photo ID” (computer vision for images).
Its core mission is to make birdwatching accessible to everyone from backyard observers to professional ornithologists while simultaneously collecting vital data for global conservation efforts.
Real-time Sound ID
Computer Vision Photo ID
Citizen Science Powered
Offline Functionality
Science-Backed
Review
Merlin Bird ID is known for being the uncontested gold standard of nature AI. Its primary strength is the Sound ID feature, which can identify multiple bird species simultaneously in real-time with staggering accuracy, even in noisy environments.
Unlike many AI tools that require a subscription, Merlin is a completely free, non-profit resource that serves both as an educational marvel and a scientific tool. While it relies on the quality of your phone’s microphone and hardware, its ability to turn a simple morning walk into an interactive masterclass in biology makes it one of the most impactful applications of AI in the world today.
Features
Sound ID
The flagship feature that displays a live spectrogram and highlights the specific bird singing in real-time.
Photo ID
Analyzes a photo taken through the app or from your gallery to suggest the most likely species.
Step-by-Step ID
Asks three simple questions (Size, Color, Activity) to narrow down a species when you don't have audio or a photo.
eBird Integration
Seamlessly connects with the eBird app to help users manage their "Life List" and contribute to global science.
Digital Field Guide
Includes professional-grade photos, distribution maps, and high-quality audio recordings for every species.
Regional Bird Packs
Specialized datasets for over 10,000 species worldwide, allowing for precise local identification.
Best Suited for
Beginner Birdwatchers
Ideal for those who hear a bird but don't know where to look or what to call it.
Nature Enthusiasts
Perfect for hikers and campers who want to learn about the wildlife in their surroundings.
K-12 Educators
An excellent classroom tool for teaching students about biodiversity and acoustics.
Backyard Observers
Useful for identifying local visitors at bird feeders and understanding seasonal migration.
Travelers
Great for international trips to identify exotic species using regional Bird Packs.
Scientific Researchers
A strong field tool for conducting rapid bird censuses and documenting rare species.
Strengths
Industry-leading Sound ID can distinguish between dozens of overlapping calls in a dense forest.
Totally free and works offline.
Interactive learning helps users build “ear-training” skills
Grounded in peer-reviewed data, ensuring that the “AI” suggestions are biologically plausible for your location.
Weakness
Hardware Dependent; a low-quality or blocked microphone can lead to missed or incorrect IDs.
Battery Intensive; running real-time audio and GPS processing can drain smartphone batteries quickly
Getting started with: step by step guide
Merlin’s workflow is designed to be instantaneous, allowing users to catch a fleeting bird song or sight.
Step 1: Download Bird Pack
The user installs the app and downloads the pack for their current region (e.g., “US: Northeast”).
Step 2: Launch Sound ID
In the field, the user taps “Sound ID” and holds their phone toward the source of the noise.
Step 3: Real-time Identification
As the bird sings, the AI highlights the species name and displays its photo on the screen.
Step 4: Verify Sight/Photo
If the bird is visible, the user can use “Photo ID” to confirm the visual characteristics.
Step 5: Explore Field Guide
The user clicks on the identified species to view maps, listen to alternative calls, and read ID tips.
Step 6: Save to Life List
The user marks the bird as “This is my bird!” to save the record to their personal eBird account.
Frequently Asked Questions
Q: Is Merlin Bird ID really free?
A: Yes. It is a non-profit scientific project and contains no ads, no subscriptions, and no paywalls.
Q: Does it work without an internet connection?
A: Yes. As long as you have downloaded the “Bird Pack” for your region, the AI can identify birds without Wi-Fi or cellular data.
Q: Can it identify every bird in the world?
A: It currently supports over 10,000 species, covering almost all birds found globally across all continents.
Q: Why did it identify a bird I know isn't here?
A: AI can occasionally have “false positives” due to wind noise or mimicry. Always use the “Maps” feature in the app to see if the bird is expected in your area.
Q: Does the app record my voice?
A: Merlin listens for bird sounds. While it doesn’t “record” your conversations for marketing, you can choose to save audio recordings to your device.
Q: What is a "Bird Pack"?
A: It is a localized database of photos, sounds, and AI models for a specific region. You must download at least one to use the app.
Q: Can it tell the difference between a male and female bird?
A: In most cases, the Photo ID can distinguish between sexes if they have different plumage (sexual dimorphism).
Q: Does it work for baby birds?
A: Identification of fledglings is difficult for AI (and humans), as they often lack the distinct colors and songs of adults.
Q: How does Merlin help conservation?
A: When you use the app, your (anonymous) sightings help scientists at Cornell track bird populations and migration patterns to protect habitats.
Q: Can I use it to identify birds from a video?
A: Currently, you can use Sound ID while a video is playing or upload a photo, but there is no direct “Video ID” feature yet.
Pricing
Merlin Bird ID is a project of the Cornell Lab of Ornithology and is completely free to use. There are no hidden subscriptions or “Pro” tiers, as the app is funded by grants and donations to support avian research and conservation.
Basic
$0/month
Sound ID, Photo ID, Offline Bird Packs, Life List integration (eBird).
Standard
Optional Donation
Supports bird research, habitat protection, and future AI development.
Pro
–
–
Alternatives
iNaturalist
A broader nature app that identifies all plants and animals, though its bird audio ID is less specialized than Merlin's.
Picture Bird
A commercial alternative with a focus on photo ID, though often requires a subscription for full features.
Audubon Bird Guide
A comprehensive traditional field guide app with some AI features, but less focus on real-time audio analysis.
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