Spek Spectrogram analyzer

Professional audio spectrum analysis and spectrogram visualization for engineers, producers, creators, and audio enthusiasts.
Spek transforms audio into a detailed visual spectrogram, allowing you to inspect frequencies, identify compression artifacts, evaluate audio quality, and explore how sound changes over time. Whether you're mastering music, verifying lossless audio, analyzing recordings, or troubleshooting noise issues, Spek provides powerful analysis tools directly on your device.
Built with performance and privacy in mind, all audio processing is performed locally on your device. No audio files are uploaded, and no analysis data leaves your device.
PROFESSIONAL AUDIO ANALYSIS
Import audio files and instantly generate detailed spectrograms that reveal the frequency content of your recordings over time.
Use Spek to:
• Verify audio quality and detect compression artifacts
• Identify frequency cutoffs caused by lossy encoding
• Check whether a file is truly lossless or an upscaled source
• Analyze background noise and unwanted frequencies
• Inspect dynamic range and spectral balance
• Examine left and right audio channels independently
• Explore detailed frequency information throughout an entire recording
SUPPORTED AUDIO FORMATS
Analyze a wide range of popular audio formats, including:
• WAV
• AIFF
• MP3
• AAC
• M4A
• FLAC
• OGG
Advanced decoding and file validation help ensure reliable analysis, even when audio files contain metadata issues or damaged container structures.
HIGH-RESOLUTION SPECTROGRAMS
Customize the analysis engine to match your workflow:
• Multiple FFT sizes (1024, 2048, 4096, 8192)
• Adjustable overlap and time density settings
• Selectable window functions including Rectangular, Hann, and Hamming
• Configurable minimum and maximum dB ranges
• Multiple color palettes for enhanced visibility
Fine-tune the balance between frequency resolution and time resolution to reveal exactly the information you need.

Navigate large spectrograms with ease:
• Pinch to zoom
• Smooth pan navigation
• Linear frequency scale
• Logarithmic frequency scale
• High-detail deep zoom rendering
• Fast viewport updates and responsive interaction
Explore both broad frequency trends and microscopic spectral details without sacrificing performance.

Listen while you analyze.
Spek includes an integrated audio player with a synchronized playhead that moves across the spectrogram in real time. Quickly correlate what you hear with what you see and locate specific events within the audio.
Features include:
• Real-time playback synchronization
• Moving visual playhead cursor
• Optional playhead following mode
• Efficient rendering for smooth performance

Visualize incoming audio directly from your microphone.
Monitor environmental sounds, voices, instruments, and test signals in real time through a continuously updating spectrogram display.
Ideal for:
• Acoustic inspection
• Noise identification
• Equipment testing
• Educational demonstrations
• Sound design experimentation

Share or archive your analysis results with high-resolution spectrogram exports.
Export:
• Full spectrograms
• Current viewport selections
• Professional-quality PNG images
Perfect for reports, documentation, presentations, and collaboration.

Spek is useful for:
• Audio Engineers
• Music Producers
• Mastering Engineers
• Podcasters
• Sound Designers
• Archivists
• Collectors
• Researchers
• Students and Educators
Whether you're validating audio sources, investigating recordings, or studying sound behavior, Spek provides the tools needed for accurate visual audio analysis.
FAST, PRIVATE, AND OFFLINE
Your privacy matters.
• No account required
• No audio uploads
• No cloud processing
• No user tracking by the app itself
• 100% local audio analysis

Audio decoding, FFT processing, and spectrogram rendering are performed directly on your device, giving you complete control over your files and data.
Download Spek today and discover what your audio really looks like.