# The free checker tool: what it tests before you upload URL: https://www.panoramr.com/help/photo-checker Category: Photos and uploads Keywords: checker tool, check equirectangular, viewer online, 2:1 checker, check before upload Last checked: 2026-11-01 What the free checker tool tests on your device before you upload: format, shape, width and file size, the verdict it gives and the preview. The [photo checker](https://www.panoramr.com/tools/360-photo-checker) is a free page, open to anyone. You give it a photo, and it tells you whether Panoramr will take that photo, then lets you look round it in 360. The photo is read on your own device and is never uploaded. It uses the same rules as the upload panel: [Photo requirements](https://www.panoramr.com/help/photo-requirements) has them in full. ## Giving it a photo ### Drop a photo here, or choose one Pick the file to check. **Where:** The checker page, in the box that says it takes a photo from your camera's app, usually a JPEG. You can also drop a file on the box. **Default:** Empty. **What it does:** Reads the file on your device. Choosing another file starts again. **What visitors see:** Nothing is sent to Panoramr. **Related:** [Upload panoramas](https://www.panoramr.com/help/upload-panoramas). ## What it checks Each check is marked with a tick (it passes), an exclamation mark (advice: it will work, with a note) or a cross (a real problem that stops an upload). ### Format Whether the file is a kind Panoramr takes. **Where:** The first line of the results, written `Format: JPEG`, `Format: TIFF` or `Format: not a JPEG or TIFF`. **Default:** Checked for every photo. **What it does:** A JPEG passes. A TIFF gets advice: Panoramr takes TIFF files, but most browsers cannot show one, so the checker cannot read its size or preview it. Anything else is a problem: export the photo again from the camera's app as a 360 JPEG. **What visitors see:** Nothing. **Related:** [Photo requirements](https://www.panoramr.com/help/photo-requirements#file-types). ### Shape Whether the photo is twice as wide as it is tall. **Where:** The results, written as `Shape:` and the photo's width and height. **Default:** Checked for every JPEG. **What it does:** Passes when the width divided by the height is between 1.9 and 2.1. Otherwise it is a problem: the picture looks flat or cropped, and you should export the full 360 (equirectangular) photo. **What visitors see:** Nothing. **Related:** [Photo requirements](https://www.panoramr.com/help/photo-requirements#shape). ### Width Whether the photo is too wide, or small. **Where:** The results, written as `Width: fine`, `Width: on the small side` or `Width: too wide`. **Default:** Checked for every JPEG it can read. **What it does:** Over the width Panoramr's servers take (16,384 pixels) is a problem. Under 4,000 pixels wide is advice: it will work, but may look soft when visitors zoom in. **What visitors see:** Nothing. **Needs:** The checker's limit is the one for Panoramr's servers. The upload panel on a computer with enough memory takes a sphere up to 23,000 pixels, so a photo flagged as too wide here can still go into a tour from a computer. **Related:** [Photo requirements](https://www.panoramr.com/help/photo-requirements#largest-size). ### File size Whether the file is small enough to work well. **Where:** The results, written as `File size:` and the size in megabytes. **Default:** Checked for every photo. **What it does:** Over 250 MB MB is advice, not a refusal: it takes longer and needs a recent computer with plenty of memory, and a JPEG at a slightly lower quality is far smaller. **What visitors see:** Nothing. **Related:** [Photo requirements](https://www.panoramr.com/help/photo-requirements#file-size). ## What it tells you ### Verdict One sentence above the checks. **Where:** The heading of the results. **Default:** Shown once a photo has been read. **What it does:** `This photo will work in a tour.` when every check passes, `This photo will work, with a note.` when there is advice, and `This photo will not upload as it is.` when any check is a problem. Under the checks, a photo that will work gets a `Make a tour with this photo` button. It opens **Create tour** in a new tab with the photo already added, and it starts at once; without an account, tick the box to agree to the terms first and it starts then. The photo goes from one tab to the other on your computer: nothing is uploaded until Create Tour uploads it. While the free trial is off, the button opens sign-up instead, without the photo. **What visitors see:** Nothing. ### Look round it Look round the photo as a visitor would. **Where:** Under the checks, with the line `Drag to look round, as a visitor would in a tour.` **Default:** Shown only for a JPEG of the right shape. **What it does:** Shows the photo in the same 360 viewer the tours use. A TIFF, or a photo of the wrong shape, is not shown. **What visitors see:** Nothing is stored. **Related:** [Upload panoramas](https://www.panoramr.com/help/upload-panoramas). ## Under the checker ### How to test a 360° image Four steps, under the box and the results. **Where:** The checker page, under `How to test a 360° image`, with links to [Level correction](https://www.panoramr.com/help/level-correction-how-to-fix-tilted-360-horizons) and to the guide to hiding the tripod. **Default:** Always shown. **What it does:** Says how to test a photo: export the whole 360 photo from the camera's app as a JPEG, drop it in, read the checks, then look round it for a tilted horizon, a seam where the edges meet and what shows below the camera. **What visitors see:** Nothing. ### Questions Six questions and answers at the foot of the page. **Where:** The checker page, under `Questions`, above the box that leads to Create Tour. **Default:** Always shown. **What it does:** Answers how to tell a 360 photo, why a phone's panorama fails, why a 360 photo looks bent in a normal viewer, what size it should be (with the checker's width limit and the file size that works best), whether the photo is uploaded, and what happens to a TIFF or six cube faces. **What visitors see:** Nothing. Search engines read the same questions from the page.