MorseKey vs RST Decoder
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
MorseKey
Practice sending Morse Code with this simple touchscreen keyer. Adjust tone frequency and volume, or use the iambic keyer for speed training. Ideal for learning and practicing Morse Code transmission.
- Touchscreen Morse code key
- Adjustable tone frequency
- Adjustable volume
- Iambic keyer (mode A)
- Adjustable dot speed
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This is a very simple touchscreen-based Morse Code straight key. Practice sending Morse Code on your iPhone or iPod Touch. Touch the display screen and the device will sound out a tone. The duration of the tone is controlled by how long you touch the device screen. Send Dots using quick touches, and Dashes by touches held down 3 times longer. The tone frequency is adjustable from 300 Hz to 1200 Hz in the Settings. The volume can be adjusted to a lower level as well. There is also an iambic keyer (mode A) with adjustable dot speed available. A Morse Code tutorial is not included. You can find one on Wikipedia or on the ARRL website. Also see MorseTest, in the iPhone App Store, another educational Morse Code application by HotPaw Productions.
RST Decoder
This application decodes Morse code from your microphone, acting as a practice tool to verify your keying accuracy. It offers advanced features like BPF and FFT decoders with automatic frequency and gain control, allowing for fine-tuning of reception parameters.
- Microphone Morse code decoding
- Morse practice and keying check
- BPF and FFT decoder options
- Auto Frequency Detector (AFD)
- Auto Gain Control (AGC)
- Real-time CW signal display
- Input signal recording/playback
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This is an App that decodes Morse code input from the microphone. It is a Morse practice App that you can use to check if you are keying the correct code. Signals with good S/N can be decoded correctly, but signals with bad S/N cannot be decoded correctly. Also, the performance will be degraded for extremely slow or fast signals. Usually about 5 to 10 characters are required for speed synchronization of Morse Code. Adjust the input signal so that the peak value changes from level 6 to level 7. Make fine adjustments to each parameter according to the reception status. [Additional Functions] -In addition to the decoder using BPF, a new decoder using FFT has been added so that it can be switched according to the usage. -AFD (Auto Frequency Detector) function has been added to the decoder using BPF, and BPF can be set automatically by pressing the AFD button. -The decoder using FFT automatically follows the strongest signal in the band by AFD (Auto Frequency Detector) and AGC (Auto Gain Control). You can also hold the AFD / AGC parameters by pressing the Lock button. * There will be a time lag of about 1 to 2 seconds for AFD tracking. [Control parameters] 1. Audio Input Level 2.BPF ON/OFF 3.BPF of Center Frequency 4.BPF of Band Width 5.CW Speed Control ON/OFF 6.CW Speed Control Low, Mid1, Mid2 or High 7.Delete All Decoded Text 8.Realtime CW Signal Display 9.Input signal recording / playback function *Japanese/KANA text is not supported. [Note] Since the signal after BPF is output to the audio output, it can also be used as an AF-CW filter. [URL of this App working example video] https://youtu.be/Pwp7W4m-m34
Screenshots
Verdict
The clearest difference is rating: RST Decoder at 5.0 against MorseKey's 4.5. RST Decoder also leads on update cadence (every 2 months vs every 12 months). MorseKey's advantage is ads (none vs shown) and monetization model (free vs ad-supported). On price, review sentiment, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
RST Decoder holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 28 and 7 respectively. Written reviews split almost evenly too, at 67% and 67% positive.
MorseKey ships an update every 12 months, RST Decoder every 2 months. The most recent releases landed on September 18, 2026 and September 8, 2026 respectively.
| Parameter | MorseKey | RST Decoder |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (28 ratings) | 5.0 (7 ratings) — better |
| Positive reviews | 66.7% of reviews | 66.7% of reviews |
| Number of ratings | 28 — better | 7 |
| Update frequency | Every 12 months | Every 2 months — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 12.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 0 MB | 6 MB |
| Age rating | 4+ | 17+ |
| Developer | HotPaw Productions | koji kamogawa |
Customer experience
MorseKey
RST Decoder
In-app purchases
MorseKey
No in-app purchases
RST Decoder
No in-app purchases









