Convert an A4 PDF to A5, scale A5 up to A4, or resize to A3, A6, US Letter, Legal, Tabloid or a custom size — with fit, fill, stretch, margins, orientation and page‑range control. 100% in your browser, files up to 200 MB, nothing uploaded. 📐
Change a PDF’s page size — A4, A5, A3, Letter, Legal & more
Resize to A3, A4, A5, A6, B4, B5, US Letter, Legal, Tabloid or Executive — or type a custom width and height in millimetres, inches or points. Because the A-series shares the 1:√2 shape, A4↔A5 conversions scale perfectly with no cropping.
Choose how content fills the new page — Fit (no crop), Fill (cover, may crop), Stretch or Actual size — set the orientation, add a margin, and resize only the pages you pick. Text stays selectable and sharp because pages scale as vectors, not images.
Everything runs in your browser with the open-source pdf-lib engine. Even a large 200 MB book PDF is resized locally — never uploaded, stored or seen by a server.
Need to turn an A4 PDF into A5 for a half-size booklet, a handout, or to print two pages on one sheet? Or scale an A5 PDF up to A4 so it fills a standard page? This free tool changes a PDF’s page size between every common paper format — and resizing every page to fit while keeping the layout perfectly centred. Beyond A4 and A5 it also converts to A3, A6, B4, B5, US Letter, Legal, Tabloid and Executive, or any custom size you type in millimetres, inches or points.
A4 measures 210 × 297 mm and A5 is exactly half of it at 148 × 210 mm. Both belong to the ISO 216 A-series, which means they share the same 1:√2 aspect ratio — so converting between them is a clean uniform scale with no cropping, stretching or white borders. The tool detects each page’s current size, scales it to the target, and centres it on the new page, preserving portrait or landscape orientation.
You get the same fit, fill, stretch and actual-size options the paid tools charge for. Fit scales content to fit with no cropping (best for A4↔A5). Fill covers the whole page and may crop the edges. Stretch forces the content to the exact dimensions, and Actual size keeps the original scale centred on the new page. Add a margin for printing and binding, force portrait or landscape, or use a page range like 1-3, 5, 8- to resize only some pages while leaving the rest untouched. There is even a scale-by-percentage mode to shrink or enlarge an entire document proportionally.
Unlike most online converters that make you upload confidential documents to a server, this one runs 100% in your browser using the open-source pdf-lib library. Your PDF is read, resized and saved entirely on your own device — nothing is transmitted, stored or seen by anyone, which matters for contracts, manuscripts, statements and personal files. It handles files up to 200 MB, so even a full illustrated book exports locally, and works on Windows, Mac, Chromebook, iPhone, iPad and Android with no install or sign-up.
Paper standards differ by country, and this resizer covers them all. In the United Kingdom, Australia, New Zealand, Ireland, Canada, India and across Europe, the ISO 216 A-series (A4, A5, A3, A6) is the everyday standard for office documents, school and university work, CVs and résumés, exam papers, invoices and government forms — so resizing a PDF to A4 or turning A4 into A5 is the most common job. In the United States and Canada, the ANSI / North American sizes rule instead: US Letter (8.5 × 11 in), Legal (8.5 × 14 in) and Tabloid / Ledger (11 × 17 in). Whenever a document crosses the Atlantic — a US Letter file opened by a UK or Australian colleague, or an A4 attachment printed in America or Canada — the page size needs converting, and you can do it here in seconds with A4 to Letter, Letter to A4, Legal to A4 and every other combination.
Whether you spell it millimetres, centimetres and metres (UK, Australia, Canada) or millimeters and inches (US), the custom-size box accepts your preferred unit, so you can resize, rescale, shrink or enlarge any PDF to the exact dimensions your printer, print shop, publisher or courier requires. It is ideal for A5 booklets, planners, invitations, recipe cards and half-page flyers, A4 reports and double-sided handouts, US-Letter contracts and Canadian bilingual forms, Australian university assignments and UK exam-board PDFs — a single free A4 ↔ A5 PDF converter and page-size changer for the USA, Canada, UK and Australian markets alike.
Converting for print? Pair it with Add Page Numbers to PDF, fix any sideways scans with Rotate & Organize PDF, shrink the result with Compress PDF, or build the document first with Merge PDF.