SimpleSSTV
Encode and decode SSTV images
Free · In-App Purchases
SimpleSSTV is a native iOS app for encoding, decoding, and live-transmitting slow-scan television (SSTV) signals — the method ham radio operators use to share images over audio frequencies.
Slow-scan television converts images to audio tones. Each pixel's brightness becomes a specific frequency between 1500-2300 Hz. Sync pulses at 1200 Hz mark line boundaries. The result is an audio signal you can transmit over any voice-capable radio, or record for later playback.
SSTV has been used by amateur radio operators since the 1950s. It's still actively used today on HF bands, VHF repeaters, and for receiving images from the International Space Station.
ENCODING (Image → Audio)
• Load any image from your photo library, camera, or Files
• Automatic resize and crop to SSTV resolution
• 21 supported modes covering all major SSTV formats
• Real-time encoding with progress visualization
• Play audio directly through speakers for VOX-triggered transmission
• Export to WAV or M4A for later use
• Optional FSK ID and CW ID (Morse code) callsign transmission
• Test pattern generator for signal testing
LIVE CAMERA MODE
• Real-time camera feed with front/back camera switching
• Three trigger modes: Continuous, Motion-triggered, or Periodic interval
• Adjustable motion sensitivity with adaptive background model
• Captures and encodes directly from camera to audio
• Keep the app in the foreground while listening or transmitting
DECODING (Audio → Image)
• Load WAV, M4A, or MP3 audio files containing SSTV signals
• Live microphone capture for real-time SSTV reception
• Automatic mode detection via VIS code identification
• Capture a transmission, then process it to see the decoded image
• FSK callsign detection from received signals
• Precision audio trimming with dual-view waveform editor
• Re-decode saved images with different mode, sync offset, or slant correction
• Handles real-world signal imperfections: timing drift, noise, sample rate variations
• Decode watermark with an automatic stamp or custom Pro text
• Waterfall spectrogram display shows signal frequency over time
SUPPORTED MODES (21 total)
• Martin M1, M2, M3, M4
• Scottie S1, S2, S3, S4, DX, DX2
• Robot 36, Robot 72, Robot BW8
• PD50, PD90, PD120, PD160, PD180, PD240, PD290
• Wraase SC2-180
ISS SSTV EVENTS
• Get notified when the International Space Station transmits SSTV images
• Automatic alerts before and during events, with frequency, mode, and callsign info
• Info card on the decode tab with event details and countdown
FAQ & SETUP TIPS
• Practical advice on audio setup and USB adapters
• Decode quality troubleshooting
• Quick reference for all 21 SSTV modes
IMAGE LIBRARY
• Automatic saving of encoded and decoded images
• Grid view with full preview, metadata, and sharing
• Re-decode any saved image with different settings
• Filter by encoded or decoded
10 LANGUAGES
Available in Arabic, Chinese (Simplified), Dutch, English, French, German, Polish, Portuguese (BR), Spanish, and Turkish — with full right-to-left support.
PRIVACY
No accounts, no analytics, no tracking. Your images and audio stay on your device. Free to encode and decode. Optional one-time Pro purchase unlocks watermark customization and Listening Station Mode. We do not use, sell or share your data for advertising or marketing purposes.
Be aware: Encoded images are audio signals — anyone receiving the audio can decode them!
REQUIREMENTS
• iOS 17.6 or later
• Camera access for live mode
• Microphone access for live decode
Built by a ham radio operator for ham radio operators. 73!
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
• Fixed Live camera mode stopping after the first image, and prevented duplicate or cancelled frames from transmitting.
• Pro users can now add custom text to decoded-image watermarks. Leave the text empty to keep the automatic stamp.
• Clearer instructions for capturing, decoding and saving received images.
The developer, Jeroen Rombouts, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Size
- 5 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.6 or later.
- iPhone
Requires iOS 17.6 or later. - iPad
Requires iPadOS 17.6 or later. - Mac
Requires macOS 14.6 or later. - Apple Vision
Requires visionOS 1.3 or later.
- iPhone
- Languages
English and 9 more
- English, Arabic, Dutch, French, German, Polish, Portuguese, Simplified Chinese, Spanish, Turkish
- Age Rating
4+
- 4+
- Contains
User-Generated Content
- In-App Purchases
Yes
- SimpleSSTV Pro 3,99 €
- Listening Station Mode 1,99 €
- Remove or change encoder watermark 2,99 €
- Provider
Jeroen Rombouts
- Jeroen Rombouts has identified itself as a trader for this app and confirmed that this product or service complies with European Union law.
- Address
Strange Loop Software
Postbus 3035
2601DA Delft
Netherlands - Phone Number
+31 634915704 - Email
info@strangeloop.nl
- Copyright
- © Strange Loop Software
