Spek Audio Spectrum Analyzer

See what your audio really contains.

Spectra is a professional audio spectrum analyzer designed to visualize the frequency content of your audio files through detailed, high-resolution spectrograms.

Open an audio file, analyze it directly on your device, and explore its spectral characteristics — without uploading your audio to a server.

🎧 Powerful Audio Analysis

Spectra helps you visually inspect audio using:

• Detailed spectrogram visualization
• Time and frequency rulers
• Spectral level visualization in dBFS
• Configurable frequency and dynamic range
• Multiple FFT/DFT window sizes
• Multiple window functions
• Channel selection for multi-channel audio
• Audio stream selection when available
• Multiple spectrogram color palettes
• Progressive analysis for longer files
• Zoom and pan for detailed inspection

📊 Understand Your Audio

A spectrogram can reveal details that aren't obvious when simply listening to a file.

Use Spectra to inspect:

• High-frequency content
• Frequency cutoffs
• Harmonic structures
• Noise and silence
• Spectral changes over time
• Compression characteristics
• Audio conversion artifacts
• Differences between various audio files

Spectra is useful for musicians, producers, DJs, audio engineers, archivists, developers, audiophiles, and anyone interested in understanding the structure of an audio recording.

🔒 Works Offline

Your audio stays on your device.

Core analysis does not require an internet connection. You can open, decode, analyze, visualize, and export supported audio files even when your device is offline.

No account is required.

📁 Broad Audio Format Support

Spectra is designed to work with a wide range of commonly used audio formats, including:

• MP3
• WAV
• FLAC
• AAC / M4A
• OGG / Opus
• AIFF
• And other formats supported by the installed decoding engine

Actual format support may vary depending on the decoder used by the app and the specific file.

⚙️ Fine-Tune Your Analysis

Choose the analysis settings that make sense for your audio.

Select from different FFT sizes to balance time resolution and frequency resolution.

Choose different window functions such as:

• Rectangular
• Hann
• Hamming
• Blackman

Adjust the displayed spectral dynamic range and choose the visualization palette that best suits your analysis.

🖼️ Export Your Spectrogram

Save your analysis as a high-quality PNG image.

Exported spectrograms can include:

• Frequency and time rulers
• Spectral color scale
• File information
• Analysis visualization

Share the resulting image with other apps or save it for later reference.

📱 Designed for Modern Android

Spectra is built as a modern Kotlin Multiplatform application with a focused analytical interface.

The design puts the spectrogram first — without unnecessary dashboards, decorative UI, or distracting controls.

Use it comfortably on phones and larger screens, with layouts designed around the available display space.

⚡ Built for Efficient Analysis

Spectra uses streaming and progressive processing so that large audio files don't need to be loaded completely into memory before analysis begins.

For longer recordings, the spectrogram can progressively appear while analysis is running.

Important Note

A spectrogram is a visualization and analysis tool. It can provide useful evidence about an audio file's spectral characteristics, but it cannot by itself prove the original source, recording quality, or authenticity of an audio file.

Spectra — Audio Spectrum Analyzer

Analyze. Visualize. Understand your audio.

Your audio. Your device. Your spectrum.