ปรับขนาด PDF ออนไลน์ฟรี

Open the tool in Chrome or Firefox, click the Upload PDF button (or drag-and-drop) and select your .pdf. After upload, choose Page Size from the right panel, pick a preset (A4, Letter, Legal) or click Custom and enter Width/Height in mm, in or px, then choose Scale content or Fit to page. Click Apply changes, wait for the progress bar to finish, and press Download PDF to save the new file. For files larger than ~50 MB the tool may upload to the server; small files are processed in-browser.

Yes — select Upload PDF, then choose Page Size → A4 (210 × 297 mm) from the preset list; you can also change units to inches (8.27 × 11.69 in). Use the Scale content toggle to shrink or enlarge page contents to the new page box; if you need margins preserved, choose Fit to page instead of Scale. Click Apply and Download PDF; typical performance is instant for files under 25 MB in Chrome, while larger files may take 30–90 seconds depending on images and pages.

Upload your .pdf and open the Page Size panel, switch units to millimeters, then click Custom and type Width: 145 and Height: 210. You can lock aspect ratio or leave it unlocked to stretch pages; choose whether to Scale content (resample images) or change the page box only (keeps original crop). Click Apply and Download PDF — note that very small dimensions can reduce embedded image quality and you can preview the first few pages before finalizing to check layout.

Upload the .pdf, then toggle on Compress PDF or open Advanced settings and choose Compression level (Low/Medium/High). Compression downscales images (for example 300 DPI → 150 DPI at Medium) and recompresses JPEG/PNG streams; choose High for maximum size reduction but expect visible quality loss on photos. The tool is free with no signup and no watermark for files under 50 MB; if your file is still too large, split the PDF into smaller parts or reduce images using the Quality slider before downloading.

Resizing page dimensions changes the page box (for example A3 → A4) and optionally scales visible content to fit; it alters layout and physical page size but not necessarily file size. Compressing reduces the file size by downsampling images, changing JPEG quality, and stripping unused objects without changing page dimensions. Use Resize when you need a specific page size for printing; use Compress when you must reduce bytes for email — you can run both: first Resize (for correct page box), then Compress (for smaller bytes).

Yes — after uploading, open the Page Range selector and enter the page numbers or ranges (for example 3,5-7) you want to change, then set the custom size or preset. The tool will apply the new page box only to those pages while leaving the others untouched; use Preview to verify pages 3 and 5–7 before downloading. Keep in mind scaling options apply per selected range — if content overlaps or clips, try toggling Scale content or adding margins to avoid cropped text.

This tool accepts only PDF input (.pdf) and outputs PDF files (.pdf) after resizing or compressing. Free usage supports files up to 50 MB and up to 200 pages per document in common desktop browsers; Chrome and Firefox handle large uploads more reliably than mobile Safari. If you upload files between 50–200 MB the tool may prompt an optional server-side process (with automatic deletion after one hour); for very large or complex PDFs, split the file into smaller chunks before processing.

Yes — Adobe Acrobat Pro offers advanced PDF optimization with finer control over image sampling, font subsetting, and object compression that can preserve more fidelity for print. Resize PDF Online Free provides simpler presets (Low/Medium/High) and image downsampling (e.g., 300→150 DPI) which is sufficient for screen or email but may introduce visible artifacts for high-resolution print. For precise prepress work keep Acrobat or InDesign for CMYK and transparency flattening; use this tool when you need a quick, free reduction without installing software.

Mobile Safari on iOS has stricter memory limits and an inline PDF preview that can block uploads; try using Chrome on Android or the desktop version of Chrome/Firefox. On iPhone/iPad, long-press the PDF in Files and choose Share → Copy to the browser app, or save the file to the Files app and then choose Upload PDF instead of drag-and-drop. If the PDF is larger than ~30 MB on mobile, split it or compress on desktop first — the tool handles larger files more reliably in desktop browsers.

Resizing the page box normally preserves embedded fonts and internal links (bookmarks and PDF annotations) because the tool modifies page boundaries and image streams rather than re-creating text. However, if you choose aggressive compression that rasterizes pages (High compression with rasterization option), text is turned into images and links/selection will be lost. If you rely on selectable text or clickable links, avoid rasterization and use Scale content without changing rendering mode; preview the first pages to confirm.

Common issues include upload failures (exceeding the 50 MB limit), clipped text after reducing page width (fix by enabling Scale content or adding margins), and missing fonts when using rasterization. If the Download button is disabled, check your browser popup/blocker or try a hard refresh; in Edge the browser may open the PDF preview instead of downloading — right-click Download and choose Save link as. For persistent failures, split the PDF into smaller files or try Chrome/Firefox on desktop where the tool has the best reliability.

It’s a convenient free web option for changing page size, applying presets like A4/Letter/Legal, and compressing PDFs without signup or watermark for files under 50 MB; it targets multipage PDFs rather than single-image editing. Photoshop can edit single PDF pages as high-resolution raster images but is overkill for batch multipage resizing, while HandBrake is a video encoder and not suitable for PDFs. For print-accurate box adjustments and preflight use Adobe Acrobat Pro; choose this online resizer for quick, free page-size changes and lightweight compression when you don’t have desktop software.