What is Merlin Bird ID?
Merlin Bird ID is a free bird identification app developed by the Cornell Lab of Ornithology. It covers thousands of species across the US, Canada, Europe, the Western Palearctic, India, and parts of Latin America and the Caribbean. The app produces species matches from photos, live audio, or a short guided questionnaire. Merlin draws on over 800 million sightings submitted to eBird and photos and recordings from the Macaulay Library. Range data comes from Birds of the World. It runs on iOS and Android, and core features including Sound ID and Photo ID work completely offline.
Features & Benefits
- Sound ID — Listen in real time to the birds around you and display a live list of species currently singing or calling. Compare your recording to reference audio in the app. Runs fully offline.
- Photo ID — Analyze a photo from your camera or camera roll and return a ranked shortlist of possible species. Runs fully on-device.
- Bird ID Wizard — Walk through three guided questions about size, color, and behavior to generate a list of likely species for any bird you’ve observed.
- eBird-Powered Location and Date Filtering — Narrow every identification method by your current location and the date, drawing on birding sightings from around the world to surface only species realistically expected at that place and time.
- Explore Birds Near You — Browse custom lists of species likely to appear at a specific location, with filters for time of year and the option to view all offline-downloaded birds.
- Life List — Save confirmed identifications to a personal life list by tapping “This is my bird,” building a running record of every species identified with the app.
- Downloadable Bird Packs — Download regional packs to enable offline access to photos, sounds, range maps, and identification text for species in your area.
- Multilingual Support — Access the app and identification text in multiple languages including Spanish, French, German, Portuguese, Chinese, Hebrew, Russian, and Japanese.
Real-World Applications
On a morning walk through a local park, Sound ID can pick up birdsong before a bird is even visible. The feature runs a live analysis in the background and flags species as they call, displaying real-time suggestions that update second by second. Tapping any result opens the full species profile with reference recordings for direct comparison, making it possible to confirm a bird identification on the spot.
Tracking down a bird photographed earlier in the day is a common scenario where Photo ID proves useful. Pulling the image from a camera roll and running it through this bird identification app returns a short list of candidate species ranked by likelihood. Each result links to range maps, identification notes written by Cornell Lab experts, and a reference photo gallery from the Macaulay Library. The entire process runs on-device.
At a nature preserve with spotty cell coverage, the Bird ID Wizard provides a reliable method for visual sightings. Answering three questions about size, color, and behavior filters the species database against location and the current date. The underlying data reflects more than 800 million eBird observations, so location-based filtering surfaces specific, field-relevant results rather than a generic global list.
Planning a trip to an unfamiliar birding region can start inside the app. The Explore feature accepts any location and date combination, generating a tailored species list before arrival. Downloading the relevant bird pack loads full offline profiles for all species in that region. Each profile includes photos, audio, range maps, and expert identification notes. Used as a bird identification app in this way, Merlin Bird ID functions as a complete field guide that works without any data signal.
During a backyard birding session, the life list feature turns each confirmed identification into a permanent record. Tapping “This is my bird” after a Sound ID or Photo ID match logs the species automatically. Over time, the list reflects every bird identified through Merlin Bird ID, tied to the locations where each identification was made.
