Comparison

SANlight vs VPD Chart

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

SANlight

Features
Read full description

The SANlight app to control the brightness of SANlight grow LEDs connected to a Bluetooth dimmer. Please note: You'll need a dimmable SANlight LED lamp connected to a SANlight dimmer to make use of this app. For feedback and support please use the "Contact Support" button on the Information screen.

About

VPD Chart

This app calculates Vapor Pressure Deficit (VPD) using air temperature, relative humidity, and canopy temperature. It offers real-time charting, sensor integration, and educational tools to understand plant growth environments. Organize data by zones and visualize dew point areas.

Highlights
  • VPD calculation
  • Interactive VPD chart
  • Sensor integration
  • Zone organization
  • Dew point visualization
  • Grow Timeline
Features
Read full description

The app calculates VPD using air temperature, relative humidity, and canopy temperature. View real-time VPD values on an interactive chart. Connect sensors for automated readings or manually input data via intuitive sliders and text inputs. Key features: • Interactive VPD chart with manual input • Default crop types • Organize charts by assigning them to different zones • Display spots that share the same VPD value • Zoom in and out of the VPD chart with a two-finger pinch and drag to pan around • VPD Target - long-press the chart to set a target VPD value • Dew point area visualization • Grow Timeline • Sync sensor historical data by importing it from sensor's app, via cloud APIs, or bluetooth • Explore sensor history by panning and zooming Supported bluetooth devices: • AC Infinity Cloudcom B2, A2, B1 • SensorPush: HT1, HT.w, HT.xw • Govee: H5051, H5072, H5074, H5075, H5100, H5101, H5102, H5103, H5104, H5105, H5174, H5177, H5179 • SwitchBot: Meter, Plus, Indoor Outdoor • Ruuvi: RuuviTag and RuuviTag Pro • Inkbird: IBS-TH1, IBS-TH1 Plus, IBS-TH2, IBS-TH2 Plus • ThermoPro: TP351, TP357, TP358, TP359 • VIVOSUN AeroLab THB1S • Shelly BLU H&T • Xiaomi Mijia 2 (LYWSD03MMC) (original and pvvx firmware) Supported devices with API connectivity: • Govee • Pulse • UbiBot • Ecowitt • Tuya • SensorPush Educational benefits: • Interactive Learning: Explore the dynamics of VPD based on changes in temperature and relative humidity by manipulating input sliders and animating the chart • Canopy - Air Temperature Link: Easily visualize and set values by linking canopy temperature to air temperature • Chart Bands Control: Toggle chart bands on/off (dew, under transpiration, prop, veg, flower, over transpiration) for a comprehensive understanding Included: 1 chart with manual input and grow timeline, device data sync & explore, default crops VPD Chart Plus subscription unlocks: • Unlimited charts • Automated VPD calculation by using sensors as the input data source • Background monitoring and Alerts (temperature, RH, VPD) • VPD history timeline, available on sensor-driven VPD charts • Custom crops Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

SANlight3 screens
VPD Chart4 screens

Verdict

The call

The clearest difference is in-app purchases: SANlight at none against VPD Chart's 2. VPD Chart's advantage is update cadence (every 3 weeks vs every 6 months). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. VPD Chart sells 2 in-app purchases, starting at $3.99 per month. SANlight asks for nothing beyond the download.

UpkeepUpdate frequency

SANlight ships an update every 6 months, VPD Chart every 3 weeks. The most recent releases landed on September 23, 2026 and September 22, 2026 respectively.

Scorecard2 real differences · 8 level
SANlight versus VPD Chart: the parameters behind the verdict, then further details
ParameterSANlightVPD Chart
PriceFreeFree
Rating—4.5 (30 ratings) — better
Positive reviews—73.7% of reviews
Number of ratings—30 — better
Update frequencyEvery 6 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS14.0 — better15.1
Further details — not scored
Size32 MB49 MB
Age rating4+4+
DeveloperMartin AnkerINNOVO DEV S.R.L.

In-app purchases

None

SANlight

No in-app purchases

2 purchases

VPD Chart

Subscriptions2
  • VPD Chart Plus (monthly)3 Days trial$3.991 Month
  • VPD Chart Plus (annual)3 Days trial$29.991 Year

Questions

Is SANlight free?
SANlight is free to download, with no in-app purchases.
Is VPD Chart free?
VPD Chart is free to download, with in-app purchases available.
Do SANlight or VPD Chart have ads?
Neither SANlight nor VPD Chart shows ads.
Which is updated more often, SANlight or VPD Chart?
SANlight ships an update every 6 months, and VPD Chart every 3 weeks. Most recently, SANlight was updated on September 23, 2026 and VPD Chart on September 22, 2026.

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