Changing a photo's filename from .png to .jpg does not convert its encoded image data to JPEG. If an upload rejects an apparently supported file, compare the extension, the browser's declared type and the file's actual byte signature. These signals can disagree, so a filename alone is not enough.
Use the local photo upload checker with your own photo or an image you are authorized to review. Download the format diagnostic worksheet for a portable example. The checker processes the selected file in the browser and does not upload it or perform face recognition.
Understand the three signals
The extension is the suffix in the filename. It suggests an intended format but can be renamed independently of the data. The browser's declared media type is another label; it may be inferred from the extension or left empty. Treat an absent label as unknown rather than automatically unsupported.
The byte signature is information within the actual file. The checker recognizes JPEG, PNG and WebP signatures for this diagnostic. A recognizable signature is one technical clue, not a complete validation that every part of the file is intact.
Browser decoding provides a further check: can this browser read the image and obtain dimensions? A readable image can still be rejected by a service's size, format or upload rules. Successful decoding does not establish identity, ownership, authenticity or a likely search match.
Follow the tested renamed-file example
The October 5 checker verification used an original synthetic PNG fixture and a copy whose extension was changed to .jpg. In the test browser, the renamed copy was declared image/jpeg while its bytes still identified PNG. The image remained decodable, and the checker reported the mismatch.
This is a deliberately constructed technical test, not a real person's search result. The original PNG and its renamed copy had the same underlying data. Their filenames differed; their actual image encoding did not.
- Original .png fixture: PNG bytes, a PNG filename extension and a readable image.
- The same fixture renamed .jpg: PNG bytes, a JPEG filename extension and a readable image.
- A genuine exported JPEG: JPEG bytes after actual re-encoding; its contents are no longer the identical PNG data.
The last row describes the conversion outcome to verify, not a claim that this checker converts files. Browser type labels can differ across environments; run the check on your actual authorized file rather than assuming every browser will label it identically.
Repair a mismatch through a real export
If the service requires another supported format, use an image editor's export or save-as function to encode a new copy in that format. Keep your original. Renaming a suffix does not perform that conversion, and placing an unsupported file inside a ZIP does not make it an accepted image upload.
Check the exported copy again. Confirm its actual format, file size and decoded dimensions. If it is no longer readable, return to the original source and inspect the export. Avoid repeatedly uploading a file whose technical state is still unresolved.
Converting or compressing an image can change quality and other file properties. Choose a copy that remains suitable for the service's documented use. This guide does not supply a universal pixel threshold or promise that a particular export will produce a search result.
Separate format rejection from other errors
The local checker tests JPEG, PNG and WebP and flags files over its 10 MB diagnostic limit. An actual search upload can have additional service-side rules, temporary network failures or account requirements. A technically readable file does not prove the complete upload flow works.
Record which stage failed: selecting the file, local decoding, sending the upload or receiving a search response. Include the exact non-sensitive error message and the observed format and size. Avoid sharing a person's image or filename in an ordinary public troubleshooting report.
Use the no-results guide when the upload succeeds but the search returns no results. That is a different outcome from format rejection. A negative search result does not prove an image has never appeared online.
Use the diagnostic without exposing the photo
The checker's CSV export contains technical facts without the photo or filename. The downloadable worksheet on this page contains only synthetic examples. Neither artifact establishes who a face belongs to or whether an image can be used with permission.
Before using the actual search product, review its privacy information and use an authorized image. If results appear, use the false-match review guide to keep similarity leads separate from identity proof. Return to AI Face Scan after resolving the technical upload issue.
Sources and maintenance
Prepared by AI Face Scan using the observed checker test and original explanatory examples, checked October 6, 2026. Review this page whenever supported formats, diagnostic limits or browser decoding behavior change. The guide does not remove metadata, edit photographs or upload selected files.
Prepared with AI assistance using the current public product and linked references. Practical checklists and illustrative examples are original planning aids. They do not establish product guarantees or replace a situation-specific review.