IRBatch

How to export FLIR One temperatures to CSV

Updated 5 November 2026

The FLIR One app shows you temperatures on the phone screen, but sooner or later you want the numbers in a spreadsheet: to compare readings over time, to attach them to a job, or to make your own chart. The good news is that a FLIR One image saved by the app is normally a radiometric JPG — it carries the raw thermal data for every pixel, not just the colours you see. This guide shows how to get those files off the phone without losing that data, and how to turn them into a CSV.

Before you start: keep the thermal data intact

The temperature data lives in hidden metadata inside the JPG. Many ordinary ways of moving photos strip it out, and you are left with a picture but no temperatures. Avoid these:

  • Screenshots of the app — a screenshot is just pixels.
  • Messaging apps such as WhatsApp or Messenger — they usually re-compress photos and drop the metadata.
  • Editing, cropping or rotating the image in a photo editor and saving it again.
  • Cloud services or e-mail settings that shrink photos ("reduce size", "optimise storage").

What usually works: save the image from the FLIR One app to the phone's photo library or files, then move the original file to your computer with a USB cable, AirDrop to a Mac, or a cloud folder that keeps originals. If you are not sure whether a transfer kept the data, the quickest test is to open the file in IRBatch's free preview — it tells you at once if the thermal data is missing.

Step by step: FLIR One images to CSV

  1. Save the originals from the app. In the FLIR One app, open the image library, select the images you need and save or share them as files. The exact menu names depend on the app version and on iOS or Android.
  2. Copy them to your computer. Use a USB cable (on Windows the phone appears as a device; on a Mac use AirDrop or the Image Capture app) or a cloud folder that keeps the original files. Put them in one folder.
  3. Check one file for free. Open IRBatch in your browser and drop one image into the page. You should see the thermal image, its maximum, minimum and center temperature, and the temperature under your cursor. If you see a message about missing thermal data instead, the transfer stripped it — try another way of copying.
  4. Set the measurement parameters if needed. The FLIR One app saves an emissivity and other settings with each image. If they were wrong for the surface you measured, enter one emissivity and reflected temperature under Settings; they apply to all images in the batch, and the CSV records which values were used.
  5. Add all images and export. With a Pro license you can select all the images in the folder and open them at once. When the batch has finished, click Download summary CSV. For the value of every single pixel, click Download temperature matrices (ZIP).

What is in the CSV files

The summary CSV has one row per image. Columns include the file name, capture date, camera model and serial number, image size, maximum, minimum, mean and center temperature (with the pixel position of the maximum, minimum and center), and the parameters behind the calculation: emissivity, reflected temperature, object distance, air temperature and relative humidity. A column shows whether you overrode the values from the file. Images that could not be read get a row with the reason instead of numbers.

The temperature matrix is one CSV per image in a ZIP file: a grid with one temperature per thermal pixel, in the same layout as the thermal image. This is what you want for your own heat maps, statistics or scripts.

Both exports can use °C or °F. If your Excel uses a comma as the decimal separator (common in Europe), choose the Excel (EU) CSV format: it uses semicolons between columns and commas in numbers, so the file opens correctly with a double click.

A note on resolution and the visual photo

A FLIR One file usually also contains a separate visible-light photo, which IRBatch shows next to the thermal image and can place in the PDF report. The temperatures, however, come only from the thermal sensor, which has far fewer pixels than the phone camera. So the temperature matrix is small compared with the photo — that is expected, not an error.

Common problems

  • "No radiometric data in this JPG" — the file was a screenshot, an edited copy or went through an app that removed the metadata. Copy the original again.
  • Strange temperatures on shiny surfaces — metal and glass reflect heat from their surroundings. That is a property of the measurement, not of the export; a correct emissivity and reflected temperature help, but cannot fully fix a reflective surface.
  • Only one image processes — the free version previews one image at a time; batch and CSV export need a Pro license.