Rotate an image and save the rotation permanently

A sideways photograph of a document is a common result of shooting with the phone held flat, and it is an easy rejection at a verification desk even when every other requirement is met.

Rotating before you compress is the efficient order. Compression re-encodes pixels, so fixing orientation afterwards means processing the file twice and paying a little quality each time.

For a slightly crooked scan, use another editor that supports fine-angle straightening or re-scan the document. This tool offers right-angle rotations only. After downloading, check that the top and bottom are correct in the application you plan to use, and keep the unedited original if you may need to make another change.

This tool exists for images handled in a hurry: no queue, no account, no upload, and a result you can verify on the spot. The explanation below is the same one we would give a colleague who asked how it works.

Pixels, DPI metadata and physical print size are distinct. For example, 35 mm at 300 pixels per inch is approximately 413 pixels, but pixels alone cannot guarantee a printer produces a 35 mm image. If the instructions also require DPI metadata or a measured print, check those separately.

On a phone, memory is the real constraint rather than any size limit. A 12-megapixel photograph is about 36 MB once decoded into pixels, so compiling a batch of twenty and holding every result in memory at once will get a mobile browser killed well before it runs out of storage. Process batches of ten to fifteen on a phone; on a laptop the same job is unremarkable.

Accepted inputs are JPEG, PNG, WebP, AVIF, HEIC, GIF and BMP images up to 50 MB each. SVG, HTML and other script-bearing formats are refused outright rather than sanitised, because a file that can execute code has no business being re-encoded — and an upload field that accepts one is a security hole rather than a feature. Several files can be queued where the workbench supports it. Batch, page and memory limits apply; check every output.

The source is decoded to pixels, rotated on a canvas and encoded as JPEG. JPEG encoding is lossy and transparent areas are placed on white. The browser applies source orientation during decoding where supported; inspect the output. Rotation decodes the image, rotates pixels and writes a new file. JPEG output is re-encoded and can lose quality; start from the original whenever possible. Check orientation in the app you will use to submit the file.