With migration in full swing and the birds at their loudest, this is the time of year you’re most likely to run into an unfamiliar song. We’ve pulled out our most popular post of the year as a guide to the slew of birdsong ID apps on the market.
For a long time, these apps weren’t much help with anything but the most obvious birdsongs — the same ones we’re most likely to recognize by ear. But the technology is advancing and the best smartphone apps do a pretty good job with the tough task of capturing the songs and instantly listing the most likely bird behind behind them.
But which is best for you? How hard are they to use? And should you go with one of the free versions or spend up to $30 a year?

Leading the field is a free app called BirdNET, which just recently launched an IOS version to go with a popular Android version that has more than a million users.
We put them all to the test and have clear rankings to share – along with a few surprises. This is a version of a post we ran last year that we think for good reason turned out to be our best-read post of the year.
Before we delve into how these services perform, it’s worth spending a couple of graphs on the scientific competition that’s behind this progress – and why the science of bird sounds is now coming into its own.
The bird ID apps are mere sideshows in a race to master the use of sound to study wildlife. The science of bioacoustics, which uses artificial intelligence to analyze audio from the wild, has become a powerful practice in field research.
Click here for our primer on bioacoustics that ran in the Washingon Post.
The discipline is fueled by the same digital advances powering the internet and has turned out to be particularly effective to study birds. That’s because birds are so vocal and can be found and researched almost everywhere.

A worthy contender is a European app called ChirpOMatic.
As several major universities, the Cornell Lab of Ornithology and a number of private companies developed bioacoustic techniques, they found they could spin off commercial phone versions that identify bird calls and songs the same way the popular Shazam app does with music.
About a dozen birdsong applications have reached market as the race to create truly reliable versions has accelerated over the past three or four years.
Today, there are about a half dozen worthy apps, including versions from the Cornell Lab, Princeton University Press, the technology company Wildlife Acoustics, a couple of European firms and several individual U.S. developers who are betting there’s money to be made on these products. Almost all are available for download for both Android and IOS phones. Other more sophisticated bioacoustic devices that can be used in birders’ yards are also under development.
While these solutions are cresting, we couldn’t find anything that ranked how accurate they are. So we spent time with each of them, testing their precision and assessing how easy they are to use. There’s one clear leader in the field, three that were right about half the time and several that were almost always wrong in our tests.
Here are our findings (and we explain our testing approach below).