How to Tell if an Image Is AI (a Practical Checklist)

The most reliable way to tell if an image is AI is to check where it came from before you study the pixels: hidden provenance data, the earliest copy online, and who posted it. Visual clues come second, because AI images keep getting cleaner, and a 2024 study cited by NIST found people judging audio, images and video did about as well as chance. Below are a three-step process, the checkers that read AI labels, a 12-point visual checklist, how to spot a real photo that AI edited, and why detector websites get it wrong.

How to tell if an image is AI in three steps

To tell if an image is AI generated, work in this order, from the strongest evidence to the weakest:

1. Check for provenance data. Upload the file to a checker that reads Content Credentials and invisible watermarks. When a signal is found, it's the strongest evidence you'll get.
2. Find the source. Run a reverse image search to find the earliest copy, the photographer, or other photos of the same moment from other people.
3. Look closely. Open the image at full size and go through the visual checklist. Treat each flaw as a clue, not proof.

Context matters at every step. An image from an account that has posted for years, with other photos from the same event, is a different case from a single viral picture from a new account.

How to check an image for AI watermarks

When you're asking "is this image AI?", a checker that reads hidden labels is the first stop. Two kinds of hidden labels exist. Content Credentials are signed metadata, based on the C2PA standard, that can record which camera or app made a file and how it was edited. SynthID is an invisible watermark from Google DeepMind embedded in the image content itself, and OpenAI adds it to images from ChatGPT too. As of September 2026, you can read them in three places:

Gemini's SynthID check has a limit: Google says it only spots watermarks from Google's AI, although other companies now use SynthID as well. For a suspected ChatGPT image, use OpenAI's page. The explainer on ChatGPT's hidden watermarks covers how those two signals work together.

What a checker result means

A detected signal is strong evidence. OpenAI calls false positives on its checker rare, and the C2PA says any change to a signed file breaks the credential's signature. A result of "nothing found" tells you very little. OpenAI's list of reasons includes lost metadata, a watermark worn down by edits or compression, an image older than these signals, and pictures from other companies' AI. Google adds that Gemini sometimes can't tell at all, for example when a picture is too simple or abstract to carry a watermark, or when an edit was too small. When you check a screenshot, Google advises cropping tight around the image and not uploading a collage of several pictures.

Find where the image came from

A reverse image search shows where else an image appears online, which often settles the question before any detector does. On a computer, Google Lens works in Chrome, Firefox, Safari and Edge.

1. In Chrome, right-click the image and click "Search with Google Lens" to see results in a sidebar.
2. Or go to Google, then drag the image file into the search box, or paste the image's address.
3. Look through the websites that show the same or a similar image. Sort out which copy came first, and whether a named photographer, a news outlet or a stock library published it.
4. Look for other angles. A real event usually leaves several photos from different people. A dramatic scene that exists in only one image, first posted by an account that shares AI art, deserves suspicion.
5. If you have the original file rather than a screenshot, check its metadata. Google notes that photos can carry EXIF data with the camera model, date and settings.

When the stakes are high, ask whoever posted the picture for the original file or a second photo taken from another angle.

How to spot AI images: 12 visual signs

These are the signs to look for when you need to tell if a photo is AI generated, roughly in the order worth checking. Google's own list of common artifacts covers garbled text, mistakes in hands, teeth and background details, inconsistent shadows and lighting, and unnatural repeating patterns. Zoom in on each area rather than judging the whole picture at phone size.

1. Text and signs. Letters that almost spell a word, a shop sign with a warped letter, or a label that turns into squiggles. Here's why AI messes up text in images.
2. Hands and fingers. Extra or fused fingers, a thumb on the wrong side, rings sinking into skin, a hand touching a cup without gripping it. More in the guide to why AI is bad at hands.
3. Teeth and ears. Too many teeth, teeth that blur into one band, and earrings that don't match from left to right.
4. Eyes and glasses. Pupils of different shapes, catchlights that show two different windows, and glasses frames that melt into the temple.
5. Hair edges. Strands that fade into the background or merge with a collar.
6. Skin. The same pore-free finish on every face in the picture. This is a weak clue alone, since real portraits are retouched too.
7. Light and shadows. Shadows falling in different directions, or a face lit brightly from a side with no window or lamp.
8. Reflections. A mirror, shop window or puddle that doesn't show what stands in front of it.
9. Background people and objects. Faces that dissolve, arms that join two people, chairs with a missing leg.
10. Repeating patterns. Tiles, bricks, leaves or crowd faces that copy each other too neatly.
11. Structure. Railings that don't connect, straps that go nowhere, windows at impossible spacing.
12. Details that don't fit the claim. Weather, uniforms, license plates and packaging that don't match the place and date in the caption.

An image with none of these flaws can still be AI. OpenAI says ChatGPT Images 2.5 renders light more naturally and adds richer texture compared with the version before it, and people use prompting tricks to make AI images look real, so a clean result proves little by itself.

How to tell if a photo is AI edited

A photo can be mostly real with one AI-made part, which is harder to spot than a fully generated image. NIST's report on synthetic content gives two common cases: an object removed with the gap filled in by AI (inpainting), and a photo extended past its original edges (outpainting). In both, most of the picture is genuine.

• A patch that doesn't match. One area is smoother, blurrier or less grainy than the rest of the photo.
• Texture that repeats. The spot where a person or car was removed often shows the same grass, brick or sand pattern twice.
• Lines that bend. A horizon, railing or tile row that kinks where an edit was made.
• Edges with less detail. Outpainted borders can look softer or more generic than the center.
• Labels in the menu. Meta files the "AI info" label for AI-edited content under the post's menu, not on the image itself.
• Edit history. When a file has Content Credentials, the Gemini app's summary can list past edits and say whether AI was involved.

Why AI image detectors get it wrong

Detector websites that give an "AI probability" score are the weakest check on this page. NIST's November 2024 report describes automated detection as a cat-and-mouse game: each new detection method is followed by better generators and new ways to dodge it. The report adds that detectors are often tied to specific generators and may work well only on those.

People aren't much better. NIST cites a 2024 study in which human judgments of synthetic audio, images and video came out near chance. The report also warns that false positives, where a real photo gets flagged as AI, can do serious harm, such as damage to someone's reputation.

So never accuse anyone because of one score. Combine a provenance check, a reverse image search and the visual checklist, and call the picture "unverified" when they don't agree.

Make your own AI vs real photo test

Practicing on a set of AI vs real photos whose origin you know shows you what the checklist catches and what it misses. Take four photos with your phone, make matching scenes with Image Generator, mix them up, and ask a friend or a class to sort them before you reveal the answers. Then go through the 12 signs together on each AI image. An image currently costs 50 credits. Toybox AI doesn't currently add watermarks to AI-generated results, so label the AI images yourself before you share the test anywhere.

A hand holding a mug, since hands are a common AI tell:

A realistic phone photo of a hand holding a white ceramic coffee mug on a wooden cafe table, early sun slanting in through a side window, steam rising from the mug, a small potted plant slightly out of focus in the background.

A storefront with lettering:

A realistic street photo of a small bakery storefront at dusk, a hand-painted sign above the window that reads "Fresh Bread Daily", warm light inside, a bicycle leaning against the brick wall, wet pavement after rain.

A mirror, to test reflections:

A realistic photo of a hallway with a round wall mirror above a narrow wooden table, the mirror reflecting a coat rack and a potted fern across the hall, soft afternoon light, a set of keys in a small dish on the table.

Results vary from image to image. If one comes out with no visible flaw, keep it in the test, since that's part of the lesson.