Which image format is best for OCR?
PNG, high-quality JPG, and WebP can all work well for OCR. Compare formats, compression, character clarity, and when conversion cannot help.
Preserve source quality before choosing a format
Screenshots and flat digital graphics often work well as PNG because edges remain sharp. Camera photos are commonly JPG or WebP. Repeatedly saving a small JPG can add compression artifacts around letters, so use the original or a high-quality export.
TIFF can preserve scanner output well, but browser tools may normalize it before processing. A format conversion is useful only when it preserves the source detail and creates a supported file. Converting a blurry image to PNG does not make its characters clearer.
File type matters less than readable character detail, which is explained in image resolution for OCR.
Inspect the smallest important text at full image size. If character strokes merge, recapture or rescan before worrying about format. Keep the original master and make a separate upload copy when privacy redaction or rotation is needed.
Choose the file by its source
Use the original PNG for screenshots and flat graphics with sharp text edges.
Use the original high-quality JPG or WebP for camera photos rather than a messaging-app copy.
Keep a TIFF master from a scanner, even if the upload copy is normalized to another format.
Format conversion cannot restore evidence
Changing a JPG filename to PNG, enlarging a small file, or exporting at a higher quality setting does not recreate strokes already lost to blur or compression. Judge the smallest required character at full size and recapture when its shape cannot be distinguished.
For interface text and messages, keep the original file and follow the steps to translate a screenshot.