# FFT

> High-resolution audio analysis tool with real-time graphing and signal generation. (iPhone/iPad app by Andrew Smith.)

- Source: https://appshunter.io/ios/app/fft/id298840058 (this page in markdown: same URL + `.md`)
- Developer: [Andrew Smith](https://appshunter.io/developer/291822462)
- Category: Music, Utilities
- Price: $10.99 with in-app purchases
- Rating: 4.00/5 from 6 App Store ratings · 36 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.0 · 21 MB
- Languages: American English, French (France), German (Germany), Japanese, Polish, Chinese (Simplified, China), European Spanish, Swedish
- Released: 2009-01-22
- Data updated: 2026-08-29
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/fft/id298840058/reviews.md

## What is FFT?

FFT is a high-resolution audio analysis tool for the iPhone and iPod touch. It uses the Fast Fourier Transform to analyze incoming audio, and displays a very detailed graph of amplitude vs. frequency. 

Use this app with the built-in iOS device microphone, or upgrade to our iAudioInterface2 or iTestMic for a complete professional solution.

*** Designed for Acoustical Analysis

This application has been designed for acoustics work, and so the bins have been normalized to octaves, to get a display that will show a flat line for pink noise. You can control both the level of graph smoothing and decay time, to get as much or as little detail as you require. 

You can also control the dB resolution of the graph, as well as the frequency range that is displayed. 

*** Includes Signal Generator

Included in this app is the engine from our Generator app, which is a low-distortion, artifact-free signal generator. The signal generator appears as a heads-up display when you tap the icon, so you can see the graph while you adjust the generator. Generate sine waves, square waves (within limits), white noise, and pink noise, optionally in psuedo-balanced mode. All waveforms are generated in real time using high-precision algorithms.

*** Cursor Readout

Move your finger across the screen to get a cursor to read out exact dB levels and frequencies.

*** Touch-GUI Controls

Use a vertical pinch-open gesture to expand the dB scale.

Use a horizontal pinch-open gesture to expand the frequency scale. 

*** Graph Smoothing

Smooth the graph by octave, 1/3, 1/6, 1/12, or 1/24 octave. Adjust the decay time from 0.5 seconds, for a very fast fluid display, to 8 seconds, or use Peak Hold or Average mode. Average mode is a true equal-weighted average, which can run continuously. 

*** Peak Tracking

Turn on Peak Tracking to have FFT automatically find a label the frequency of the highest peak on your graph.

*** Tune the Parameters

Set the FFT size from 4096 to 32k points (depending on iOS device) , or select Equal Points Per Octave mode, for high-resolution analysis, even at low frequencies.

*** Calibration

FFT comes calibrated for the typical iPad, iPod touch, or iPhone microphone, and you can adjust the calibration. Microphone compensation files tailored to each iOS device are automatically applied.

*** Save and Recall

When your analysis is complete, you can save the graph image to your photo roll to include in a report, or export the data in an XLS file.

*** Display Multiple Graphs

Show a recalled graph on the screen in a different color.

*** Difference Mode

Use a stored graph as a baseline that is subtracted from the current graph in real time.

*** RTA or FFT? 

If you are wondering if you should download this app or our FFT app, check out our website, we have a page devoted to this topic.

*** Other Audio Apps

Also, check out our other great audio and acoustics apps: AudioTools, our premier suite of audio and acoustics analysis apps, SPL, SPL Graph, for recording SPL over time, RTA, RT60, Generator, and Speaker Pop.

## Key features

- High-resolution amplitude vs. frequency graph
- Built-in low-distortion signal generator
- Adjustable graph smoothing and decay time
- Cursor readout for dB and frequency
- Save and export analysis graphs and data
- Peak tracking for highest frequency identification

## Pricing and in-app purchases

Base price: $10.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Reference Curve Files | $9.99 | one-time |


## Recent user reviews (10 of 36)

All indexed reviews: https://appshunter.io/ios/app/fft/id298840058/reviews.md

### 2/5 — andrewr

*2024-04-23*

Great app but it’s crashing with my update to iOS 17.4.1

### 5/5 — Amazing app!

*2021-10-24*

I’ve been using this app for a looooong time. This is an amazing app that is definitely starting to show its age but remains extremely useful.

### 5/5 — I put that s% t on everything

*2021-04-22*

Aka: I use this app for all sorts of troubleshooting. Trying to find a slow leak in a tire or a vacuum leak on an engine. By showing the peaks in Hz you can visually "see" the sound in a way impossible to hear with your ears. Priceless tool for debugging anything that makes noise.

### 2/5 — Not exactly a real discrete FFT

*2020-12-11*

The spectrum is displayed as a continuous graph rather than being discrete vertical lines for each frequency present. Makes it very hard to use for real quantitative analysis.   Why could they not have done it the correct way??

### 5/5 — 求めていたとおり

*2016-02-13, version 5.2*

細かく周波数を測定でき、日本語対応もしているのでバッチリです。
アプリ推奨のマイクで正しく測定でき、欲しいものがみつかり、嬉しいです。
あと、できればジェネレーターで正弦波を出力するとき、プリセットで8個程度登録できれば最高です。(多ければ多いほどいいです)

### 5/5 — Sehr schön

*2015-06-27, version 5.0*

Gut gemacht.

### 5/5 — 最新升级的版本问题

*2015-03-05*

您好！最新的版本应用在ipad air2 中不能使用

### 3/5 — 3 Holzbergersterne 128GB iPad 64GB iPhone 4s iOS 8.0.3 deutsch/english

*2015-03-02, version 4.9*

Seit Jahren Updates, aber nicht wo es wirklich nötig ist. Bitte auch die deutsche Sprache hinzufügen. Danke / For years, updates, but not where it is really needed. Please add the German language. Thank You

### 1/5 — Musical pitches are not correct

*2014-11-27, version 4.8.1*

This appears as if it could be a good app.

Severe let down, is that it incorrectly labels the musical notes. Using the apps own signal generator to create a 440hz sine wave, which is generally used for middle A, the app labels it as a G# . It seems to be a semi tone out for all of its pitches. 

I hope this is can be remedied ASAP with an update.

Will change my review when it does.

### 5/5 — Great app

*2014-09-19*

Help me set up my hi Fi stereo with just my iPad. Lots of options and easy to use!

## Frequently asked questions about FFT

### What does the FFT app do?

This app is a high-resolution audio analysis tool that uses the Fast Fourier Transform to analyze incoming audio. It displays detailed graphs of amplitude versus frequency, allowing users to understand the spectral content of sound.

### What are the key features of this audio analysis app?

Key features include a high-resolution amplitude vs. frequency graph, a built-in low-distortion signal generator, adjustable graph smoothing and decay time, cursor readouts for precise dB and frequency values, and the ability to save and export analysis results. It also offers peak tracking to identify the highest frequency peaks.

### How is this app monetized?

The application is available for free, but offers in-app purchases. These likely provide access to advanced features, professional hardware integration, or expanded functionality beyond the core analysis tools.

### What devices is this app compatible with?

The app is designed for the iPhone and iPod touch. It can utilize the built-in iOS device microphone, and also supports professional audio interfaces like the iAudioInterface2 or iTestMic for enhanced performance.

### What are common use cases for this audio analysis tool?

Common use cases include acoustical analysis for sound engineers and acousticians, troubleshooting audio systems, sound design, and educational purposes for understanding audio frequencies and amplitudes. The signal generator can also be used for testing audio equipment.

## Version history (last 5 releases)

### 7.8 — 2025-12-27

-Fixed a possible crash on launch

### 7.7 — 2025-12-22

-Bug fixes and stability improvements

### 7.6 — 2025-11-24

-Updated for new iOS devices
-Bug fixes and stability improvements

### 7.5 — 2024-11-24

-Updated for latest iOS devices and calibrations
-Bug fixes and operational improvements

### 7.4 — 2024-10-17

-Updated for latest devices and iOS versions
-Bug fixes and stability improvements

## Apps similar to FFT

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Audio Spectrum Analyzer Pro](https://appshunter.io/ios/app/audio-spectrum-analyzer-pro/id1152352806) | 4.4 (238) | Free | Music |
| [n-Track Tuner](https://appshunter.io/ios/app/n-track-tuner/id409786458) | 4.7 (3,166) | Free | Music |
| [Tone Generator: Audio Sound Hz](https://appshunter.io/ios/app/tone-generator-audio-sound-hz/id1206449238) | 4.7 (2,583) | Free | Music |
| [Audio Spectrum Analyzer dB RTA](https://appshunter.io/ios/app/audio-spectrum-analyzer-db-rta/id1281873790) | 4.5 (3,042) | Free | Music |
| [Audio / Spectrum Analyzer](https://appshunter.io/ios/app/audio-spectrum-analyzer/id1508848574) | 4.6 (1,013) | Free | Music |
| [iAnalyzer](https://appshunter.io/ios/app/ianalyzer/id335449113) | 4.2 (74) | Free | Music |

## More apps by Andrew Smith

- [Speaker Polarity](https://appshunter.io/ios/app/speaker-polarity/id293263027)
- [SPL](https://appshunter.io/ios/app/spl/id293573990)
- [RTA](https://appshunter.io/ios/app/rta/id298839433)
- [RT60](https://appshunter.io/ios/app/rt60/id298840320)
- [Generator](https://appshunter.io/ios/app/generator/id298840802)

All apps by Andrew Smith: https://appshunter.io/developer/291822462

## Related topics

[fft](https://appshunter.io/ios/topics/fft) · [fft audio](https://appshunter.io/ios/topics/fft-audio)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*