Turnitin AI Indicator States: Blue, Gray Dashes, and the Error — What Each One Means

There are three official states for the AI writing indicator in the Similarity Report, and they mean three different things:

• Blue with a percentage (0–100): processed successfully. The percentage is the share of qualifying prose text the model judged AI-generated — not necessarily the share of the whole document.
• Gray with dashes (--): the indicator could not process this submission. The AI writing report cannot be opened. The two official reasons are a submission made before April 4, 2023 (the release date of Turnitin's AI writing detection) or a file that does not meet the requirements.
• Error icon (!): Turnitin failed to process the submission. The report cannot be opened. The documented advice is to try again later, and to contact support if the file meets every requirement and the error persists.

A gray dash is not a score of zero. An error icon is not "still loading". Both mean the report is not there — the difference is why.

The confusion is built into the interface, and Turnitin's own pages model it: the Similarity Report has color-coded percentages, the AI indicator has its own three states, and the words overlap — "gray", "dash", "unavailable", "error" all appear somewhere.

The concrete mismatches that show up in real reports:

• A student sees a gray "--" and reads it as "0% AI" — it is not a percentage at all.
• An instructor sees the error icon during processing and reads it as "the student broke the file" — the official known-issues pages document a case where the error message appears briefly during processing even when the submission is fine.
• A student with a pre-April-2023 submission sees "unavailable" and re-uploads the same file hoping it will process — the file was never the problem; only resubmission to an active assignment can produce an AI report on a historical paper.

The way to stop mixing them up is to stop reading the states as percentages. Two of the three states are not scores. They are status messages.

Turnitin's AI Writing Detection page describes the indicator this way, after a short processing period:

Blue with a percentage between 0 and 100 — "The submission has processed successfully. The displayed percentage indicates the amount of qualifying text within the submission that Turnitin's AI writing detection model determines was generated by AI." The page adds that this percentage is not necessarily the percentage of the entire submission — non-prose text (tables, bullet points, code, poetry) is not included. The AI writing report itself is the list of prose sentences highlighted in blue.

Gray with no percentage displayed (--) — "The AI writing detection indicator is unable to process this submission." The report cannot be opened. The page names the causes: a submission before the April 4, 2023 release, or a file that does not meet the requirements for AI writing detection.

Error (!) — "This error means that Turnitin has failed to process the submission." The report cannot be opened. The page says to try again later, and to contact support if the file passes all the requirements and the error still appears.

The gray state has its own dedicated help-center page with the same three-part structure: what it looks like, why it happens, and how to generate the report anyway (resubmit, or fix the file).

The gray and error states are the interface's way of saying "this file could not be checked." The requirements list comes from the same page, and it is worth writing out because it is the checklist for what to fix:

• File size must be less than 100 MB
• File must have at least 300 words of prose text in a long-form writing format
• File must not exceed 30,000 words
• File must be written in English
• Accepted file types: .docx, .pdf, .txt, .rtf

Any submission outside these limits gets no AI percentage — not a low percentage, no percentage at all. If your file meets every requirement and you still see gray dashes or an error, the remaining named causes are the historical-submission case (pre-April-2023) or a processing failure worth contacting support about.

The right action is different for each state, and the wrong action is usually "resubmit the same file."

Blue with a percentage — the report is ready. Open it, read the highlighted prose sentences, and check whether the percentage and the highlights match your sense of the document. A low percentage with no highlights, or a percentage that looks high, are both real reasons to look at the report itself rather than the indicator.

Gray with dashes — check the two causes. Was the submission made before April 4, 2023? Then only resubmission to an active assignment can generate an AI report. Does the file meet the requirements? If not, fix the file and resubmit. If both checks pass, the gray state may be a processing delay — the known-issues pages document a temporary "unavailable" message during processing that resolves on its own.

Error icon — the documented sequence is short: try again later; if the file meets the requirements and the error persists, contact Turnitin support. The error is a processing failure, not a verdict about your writing.

Two of the three AI indicator states are not scores. Gray dashes say "this submission could not be processed for AI detection," and an error icon says "processing failed." Both have named causes — historical submission, file requirements, or a processing failure — and each has a documented next step. Blue with a percentage is the only state where a report exists, and even then the percentage counts only qualifying prose, not the whole document.