The HotPaw Morse Code Decoder translates Morse Code sound into text. Just use the microphone or headset input on your iPhone or iPad for the audio signal input, and watch decoded text appear.

The Morse Code Decoder includes both an automatic decoding mode, plus manual controls to allow the decoding of weaker signals in noise and QRM. Manually adjustable parameters include the frequency of the audio filter, the WPM dot/dash speed used for detecting characters, the threshold level of background noise, and whether Farnsworth timing is to be used for detecting spaces between individual characters.

The Morse Code Decoder includes a built-in spectrogram to help determine the audio frequency of the Morse Code tones. Use the optional narrow-band DSP audio filter to help filter out background noise. The audio filter works for tone frequencies from 300 to 2400 Hz. Please do not try to decode tones outside this range.

The Morse code WPM (words per minute) detection speed is automatically adaptive from about 8 to 40 WPM, and can be locked to the current estimated WPM dot speed. You can also manually set the WPM code speed if the automatic speed detection guesses incorrectly. A QRQ High Speed WPM mode setting allows decoding much higher WPM speeds in the range of 30 to 80 WPM.

Please aim your iPhone microphone at the Morse Code sound source so that the iPhone's noise cancelling microphone doesn't cancel it out. You can see if sound is getting to the iPhone by seeing a peak in the spectrum display. Please use the manual settings if automatic decoding does not adjust to the frequency, WPM. or background noise threshold level properly. Decoding will not work if the audio filter or WPM are set incorrectly, or there is a lot of background noise or room echoes above the threshold setting. Please see the help file on the HotPaw website for hints as to how to solve decoding issues.

What’s New

Version 2.5.3

Bug fix for text scrolling.
The previous 2.5.2 update extended the range of the audio filter setting.

Ratings and Reviews

3.4 out of 5
33 Ratings

33 Ratings

Red Culver ,

Works great if you set it right.

I have a Yaesu ft 857. I hav to change my receiver to 700hz or the iPhone WILL NOT hear the CW. I also find it useful to set the manual speed a little above the current words per minute. A person can spend his whole life developing a CW decoder and it will never work like what’s in between your ears. It really has a hard time decoding sloppy straight keys but extremely well with iambic decoding. It decodes straight key practice oscillator with precision sending. Most people use paddles or sticks anyway. This app is great for backup when I’m focused on a letter and now 14 letters behind and can jut glance over to catch up again. Apps absolutely worth the money. Maybe not the big app but this one is great. I’m extremely happy. Waaaay cheaper then a decoder on $15k radio that barely works and some commercial one that works poorly too. You shouldn’t regret it, (use manual settings) I don’t!

Straight Key ,

QRP'ers Panadaptor

During the ARRL International DX contest I found it useful while operating QRP as I manually tuned looking for stations. The ability to rapidly and visually tune stations within the passband made for efficient operation and the capability to decode speeds beyond my own ability certainly helped to get some exchanges correct that might have otherwise been iffy. After the success I had, I purchased the pro-version, since I was happy to support Hot Paw's programming efforts and hope to encourage them to develop other high quality software for digital modes to include FSQ which is of interest here for emergency operations.

rhymeswithsilver ,

You’ve tried the rest, now try the one that actually works

I tried a lot of the free and cheap CW decoder apps, but nothing worked or worked reliably. I bit the bullet on this $10 purchase and I’m glad I did.

I placed this next to a 60-meter radio with a poor signal, and this decoded the signal almost perfectly. 73, HotPaw!

The in-app documentation is a wall of text, but it’s easy enough to figure out on the fly.


Ronald Nicholson
3.7 MB

Requires iOS 9.3 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© 2018 HotPaw Productions


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