Rectify

For building façade photos

Straighten a photo. Measure it.

Photograph a building from the street. Rectify takes out the perspective, you give it one length you know, and every other distance, angle and area reads straight off the image.

or drop one anywhere on this page

No photo to hand?

  • Photos never leave this device
  • No account, no cookies

How it works

From a street photo to a take-off.

  1. 01Load a photo

    Rectify finds the façade’s vertical and horizontal lines, works out where each family converges, and re-projects the photo head-on. True proportions are kept, so one known length scales the whole image.

    Detection off? Drag four corners onto anything rectangular and it solves from those.

  2. 02Set the scale

    Trace a feature whose length you know, such as a door, an opening or a run of brickwork, and type it in. A magnifier appears while you place each end.

  3. 03Measure and export

    Distances, angles and areas, named and listed as you go, and recalculated at once if the scale changes. Export an annotated PNG or a CSV take-off schedule.

On site

Built for survey work.

  • Photos never leave the device

    Everything runs in your browser. No uploads, no analytics, no cookies, no accounts.

    Read the privacy note

  • Picks up where you left off

    Close the tab or reload and the photo and its measurements are still there, kept on this device. Turn that off, or clear it, in Settings.

  • Tells you when to doubt it

    A dot beside the file name reports how well the correction is supported. Open it for the full report, including a check of the focal length against the photo’s EXIF data.

Accuracy

Know its limits.

Rectify is a survey aid. Its answers hold under these conditions.

  • One plane at a time

    Measurements are exact only on the façade plane. Balconies, reveals and set-back walls are displaced.

  • Lens distortion stays in

    Phone cameras correct it before you see the photo. With a dedicated wide-angle lens, undistort first.

  • Scale from your longest known length

    Choose one near the middle of the façade, then check a dimension in the other direction.

  • Verify what matters on site

    Anything with structural, contractual or safety consequences needs checking in person.

Straighten your first photo.

or drop one anywhere on this page

No photo to hand?

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