# LUX - Illuminance Meter — Light meter, anywhere

> Measures ambient light intensity in lux and foot-candles. (iPhone/iPad app by koji torishima.)

- Source: https://appshunter.io/ios/app/lux-illuminance-meter/id1631156210 (this page in markdown: same URL + `.md`)
- Developer: [koji torishima](https://appshunter.io/developer/1622793467)
- Category: Productivity, Lifestyle
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 18.0 · 17 MB
- Languages: American English, Japanese
- Released: 2022-07-02
- Data updated: 2026-08-26
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/lux-illuminance-meter/id1631156210/reviews.md

## What is LUX?

LUX is a light meter app that measures illuminance (lux) wherever you are. Open the app and instantly see how bright your space is.

When to use it
- Check lighting in your living room, office, or study area
- Set up photography or video shoots
- Compare brightness between rooms or times of day
- Verify light levels for plants or aquariums
- Confirm any task has the right brightness

Features
- Instant measurement on launch
- Hold the value or freeze the screen
- Color temperature (CCT / Kelvin) measurement
- Auto-recorded Min / Avg / Max lux during a session
- Foot-candle (fc) unit toggle
- Measurement history (Premium)
- CSV export (Premium)
- PPFD reading for plant lighting (Premium)

Measurements are processed on-device.

Terms of Use: https://lux-support.web.app/en/terms-of-use.html
Privacy Policy: https://lux-support.web.app/en/privacy-policy.html

## Key features

- Instant lux measurement
- Color temperature (CCT) reading
- Foot-candle unit toggle
- Min/Avg/Max lux tracking
- Measurement history (Premium)
- CSV export (Premium)

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Monthly Plan | $1.99 | per month |
| Yearly Plan | $11.99 | per year |


## Recent user reviews (9 of 9)

All indexed reviews: https://appshunter.io/ios/app/lux-illuminance-meter/id1631156210/reviews.md

### 2/5 — ん‥

*2026-03-06*

インカメラとアウトカメラで全く違う数値を表示するんですけど。

### 2/5 — Not working much

*2025-11-21*

Very unprecise. If you point to a white surface will tell you much more than if you point to a grey or black surface. That is not how lux works

### 5/5 — 植物育成ライトの明るさを測る

*2025-10-19*

カンタンにルクスを測るのに使わしてもらってます。
他のアプリとは少し値は違いますが使いやすいです。

### 5/5 — 便利

*2025-10-07*

簡単に照度測定できて良いです。暗いところの照度は古いスマホでは測定できず、新しいスマホだと3ルクスくらいから測れる

### 5/5 — 広告なしバージョン

*2025-09-23*

課金で広告を無くせるといいですね

### 3/5 — 暗い所が…

*2024-03-07*

明るいところも、なかなか他のアプリ達もバラバラ表示なんですが、暗い所、特に10ルクス以下の時の表示が明らかに一桁違います。
  光源よりも床の方が明るいとか…
なんとかなりませんかね

### 5/5 — 使える

*2023-08-02*

ちょっと測る程度には困らないくらいに使えます。
他アプリの様に数日で課金必須になったり、広告出まくりって感じじゃない様子。

### 1/5 — 使えない

*2023-03-02*

数値が全く違う

### 5/5 — とりあえず使えそう

*2022-10-19*

簡単に照度の測定したかったので
測定したい部分に光沢の無い普通の白い紙を置いて、その紙が表示画面全体になるようにしてその反射光を測ると安定した数値で測定できました。
普通にそのまま写真の様にイメージで見てしまうと画面全体のどこを測定しているのかわからなるしバラツキが大きいので。
絶対値が合ってるかどうかはわかりませんが、相対値として簡単に安定的に値が取れるので十分使えます。

**Developer response:** URKlabo様

この度はレビューただき誠にありがとうございます。

いただいたご意見を元に、改善させていただきます。

引き続きよろしくお願い致します。

## Frequently asked questions about LUX

### What is LUX used for?

LUX is a light meter app that measures illuminance (lux) in your surroundings. It's useful for checking lighting in rooms, setting up photography, verifying light for plants, and ensuring tasks have adequate brightness.

### Does LUX have ads?

Yes, LUX contains advertisements. As a free app with in-app purchases, advertisements are displayed to support its development and availability.

### What are the premium features in LUX?

Premium features in LUX include measurement history, CSV export of data, and PPFD readings specifically for plant lighting. These advanced tools are available through subscription plans.

### How much does LUX cost?

LUX is free to download and use with basic features. Premium features are available through a monthly subscription for $1.99 or a yearly subscription for $14.99.

### What devices does LUX support?

LUX is currently supported on iPhones. The app is designed to leverage device sensors for accurate light measurements.

### How often is LUX updated?

The latest version of LUX is 2.2.2, last updated on May 24, 2026. Updates typically bring new features, bug fixes, and performance improvements.

### Can I export my LUX measurements?

Yes, CSV export is available as a premium feature in LUX. This allows users to save and analyze their measurement data outside of the app.

### What is the age rating for LUX?

LUX has an age rating of 4+. This indicates it is suitable for children and adults, with no mature content.

## Version history (last 5 releases)

### 2.3.0 — 2026-06-23

- Added "Lifetime Pro" — a one-time purchase that permanently removes ads and unlocks history, CSV export, and PPFD.
- Added a 7-day free trial to the monthly and yearly plans.
- Paywall and purchase-flow improvements, plus bug fixes.

### 2.2.2 — 2026-05-24

What's new

- Color Temperature (CCT)
  See the light source's color temperature (K) in real time. Helpful for photography, plant growing, and indoor environments.

- Auto-recorded Min / Avg / Max
  Automatically tracks the minimum, average, and maximum lux during a session.

- Foot-Candle (fc) Unit
  Switch between lux and fc in Settings (1 fc = 10.764 lux). Aligned with North American lighting standards.

- Onboarding & What's New
  Refreshed first-launch intro, and a NEW badge to revisit new features anytime.

### 2.2.1 — 2026-05-04

・bug fix

### 2.2.0 — 2026-04-27

・Premium features added: measurement history, CSV export, and PPFD display                                                
・Redesigned measurement screen with clearer glare level and PPFD layout
・Improved paywall and purchase flow                                    
・Ad display improvements and minor bug fixes

### 2.1.1 — 2026-03-11

・Introduced a new ad-free plan.

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## More apps by koji torishima

- [ChatMemo](https://appshunter.io/ios/app/chatmemo/id1622793465)

All apps by koji torishima: https://appshunter.io/developer/1622793467

## Related topics

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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 2026-08-26.*