Resize PDF to Legal Size converts every page of a document to US Legal, 8.5 by 14 inches, or 612 by 1008 points in PDF terms. Legal paper is still required in parts of North America for contracts, leases, real estate disclosures and some court and government forms, and print shops and e-filing systems often expect the file to already be in that format. Legal has the same width as Letter but is 3 inches taller, so the right setting depends on where the pages come from. For a Letter document that must be filed on Legal paper, Add white space is usually what people want: the content keeps its exact printed size and the extra 3 inches become white space, 1.5 inches above and below, so signature lines and form fields stay where they were measured. Fit to size also leaves Letter content at full size, since Letter is already as wide as Legal, while an A4 page is enlarged by about 3% to fill the width. Landscape pages can be given Legal landscape, 14 by 8.5 inches, which suits wide spreadsheets and schedules. Before anything changes, the tool reports which pages are not Legal yet, so a bundle of mixed exhibits is normalised in one pass. The conversion runs entirely in your browser and the document is never uploaded. To go back to the shorter format use Resize PDF to Letter Size, to remove empty margins use PDF Crop & Resize, and to put exhibits in order before converting use PDF Merger.
The reason inconsistent page sizes are so annoying is that nothing warns you about them. A PDF viewer happily renders a file where page 4 is Letter and the rest are A4, and the difference is only 6 mm wider and 13 mm shorter, which is invisible on screen. The cost arrives at the end of the process: a print driver set to "actual size" produces pages with different margins, a duplex job feeds wrongly, a submission portal that validates page dimensions rejects the upload, or a reader sees the page jump as it scrolls. Most PDF services offer resize, crop and compress as separate operations and leave the diagnosis to the user, which is the hard part. This tool inverts that order. It measures first, tells you in plain language what it found, and offers one button that applies the obvious fix. Only if you want something else do the other options matter. A few practical notes. Scanned pages rarely match a standard format to the decimal, so sizes within roughly 0.7 mm of each other are treated as the same format rather than reported as separate groups; this keeps the summary honest instead of listing twenty near-identical sizes. Pages carrying a rotation flag are measured as the reader sees them, so a portrait page rotated 90 degrees is correctly grouped with the landscape pages. The output is a standard PDF that opens in Acrobat, Preview, Chrome and any mobile reader, with text, fonts, links and images preserved. If your real problem is uneven white margins rather than uneven page sizes, PDF Crop & Resize is the better tool, since it trims the margins directly. If pages came from several source files, run PDF Merger first and normalise the combined document in one pass, and use PDF Page Count Checker to confirm the final file has every page you expect.