Before sending a screenshot to an AI assistant, inspect the edges
Before sending a screenshot to an AI assistant, inspect the whole image, including browser tabs, notifications and background windows. The detail you need explained may be surrounded by account information or someone else's message.
The CNIL's guidance on generative AI encourages examining the data supplied to these systems and the conditions under which it is used. A screenshot deserves the same attention as text pasted into a conversation.
The useful detail is often a small part of the image
Imagine asking an assistant to explain an error message in a browser. The screenshot also includes a signed-in email address, another customer's name in a sidebar and several document titles in open tabs. None of those details may be necessary to explain the error.
Before editing the image, decide what the assistant actually needs. A transcription of the error and a short description of the action that preceded it may be sufficient. If layout matters, a cropped copy can preserve the relevant arrangement without showing the whole workspace.
| Area to inspect | Examples of incidental information |
|---|---|
| Browser chrome | Tab titles, account indicators and address-bar parameters |
| Sidebars | Contact names, projects and recent documents |
| Main panel | Customer details adjacent to the relevant message |
| Notifications | Incoming messages or calendar information |
| Image edges | Details left visible after an incomplete crop |
These are examples to look for, not a claim that every screenshot contains them. The point is to inspect the actual file rather than relying on what you remember seeing on screen.
Prepare a copy and reopen it
Work on a copy so the original remains available where you are authorised to retain it. Remove the unnecessary regions, export the result and reopen that exported file. Check both that the sensitive detail is absent and that the useful detail is still readable.
An editing preview is not the final attachment. It is possible to select the original file by mistake, export to another location or leave part of a field visible. Looking again at the exact file selected for upload catches those simple failures.
Do not describe an image as anonymous solely because a name was removed. A combination of visible details can still identify a person or account. If the task can be explained without an image, a short text description avoids many incidental disclosures.
The CNIL's guidance on generative AI provides the broader context for examining what data is supplied to the service. Your upload review should also consider the service's actual settings and intended use, rather than assuming that all assistants handle attachments identically.
Keep enough context for a useful answer
Cropping too aggressively can create a different problem: the assistant sees a message but not the control or sequence that explains it. Add a concise description of what you did, what you expected and what happened. You can usually provide that context without revealing an entire account.
For example, describe a failed file import using its format and the visible error text. Avoid uploading an unredacted customer spreadsheet merely to show that a column was rejected. If a synthetic row reproduces the issue, label it as a test example.
After sharing, deleting the local screenshot does not itself establish that the recipient service has deleted its copy. If you need to act on data already supplied, use the relevant service controls and data-rights procedure. Keep that separate from the preventive check performed before the next upload.
Inspect the visible surroundings
Pay particular attention to information about someone else. Your wish to obtain help does not make their details necessary to the task.
Consider the service context
Review the relevant data settings and conditions of the assistant you intend to use. A setting in one account or product should not be assumed to apply to another.
If the screenshot concerns an employer, client or restricted system, follow the applicable rules for that material. When a general description can answer the question, it may be the simplest way to avoid transferring the image.
If the image has already been shared and you want to act on the data held by the service, consult the overview of data rights, available in French.
