What PDF version conversion actually does

A PDF version number tells you which features the file can contain and which software can open it reliably. Version 1.4 was released in 2005 and added support for transparency, better compression, and interactive forms. Anything version 1.4 or higher will open in modern readers without losing content or formatting.

Converting an older PDF (usually 1.3 or earlier) to 1.4 or higher does not change what the document looks like. It rewrites the internal structure so newer software can handle it better and so the file may compress to a smaller size. If your PDF already says 1.4, 1.5, 1.6, 1.7, or 2.0, you do not need to convert it.

You might need this conversion if you are sending a PDF to someone with modern software, if a tool refuses to process your file, or if you want to add interactive elements like form fields or buttons that only work in newer versions.

Key Takeaways

  • Check your PDF's current version first by opening Properties or Document Info in your PDF reader — conversion is only necessary if it shows 1.3 or earlier.
  • Adobe Acrobat (the paid version, not the free Reader) can convert PDFs by saving the file as a newer version through File > Save As > Adobe PDF.
  • Free online converters and desktop tools like LibreOffice, Ghostscript, and ILovePDF can also change the version, though results vary by tool and file complexity.
  • The conversion process takes seconds to minutes and produces a new file; your original remains unchanged.
  • After conversion, verify the new version by checking Properties again to confirm the change took effect.

How to check your PDF's current version

Before you convert, open your PDF and look at its properties. In Adobe Acrobat Reader (the free version), go to File > Properties. In the Description tab, you will see "PDF Version" listed near the top. Write down the number you see.

On a Mac using Preview, open the PDF and select Tools > Show Inspector. The version appears in the General section. On Windows, right-click the PDF file itself, select Properties, then Details tab, and look for "PDF Version" in the list.

If your version is already 1.4 or higher, you are done — no conversion needed. If it shows 1.3 or earlier, or if the version field is blank, proceed with conversion.

Converting with Adobe Acrobat (paid version)

If you own Adobe Acrobat (not the free Reader), this is the most straightforward route. Open your PDF in Acrobat, then go to File > Save As > Adobe PDF. A dialog box will appear with options.

Look for a dropdown or button labeled "Settings" or "Options." Click it and select a PDF version from the list — choose 1.4 or any higher version (1.5, 1.6, 1.7, or 2.0 all work). Then click Save and give the file a new name so you keep the original.

Acrobat will process the file in a few seconds. When it finishes, check the new file's properties to confirm the version changed. This method works reliably for almost all PDFs, including those with images, forms, and embedded fonts.

Converting with free desktop software

LibreOffice is a free office suite that can open and re-save PDFs. Open your PDF in LibreOffice Draw, then go to File > Export as PDF. In the dialog that opens, look for "PDF Version" and select 1.4 or higher from the dropdown. Click Export and save with a new filename. This works well for text-heavy PDFs but may lose some formatting in complex files.

Ghostscript is a command-line tool that converts PDFs with precision. If you are comfortable using a terminal or command prompt, you can run a single command to convert your file. On Windows, Mac, or Linux, the command looks like this: gswin64c -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -o output.pdf input.pdf. Replace "input.pdf" with your filename and "output.pdf" with what you want to call the new file. This method is fast and reliable but requires some technical comfort.

Both tools are free and open-source. LibreOffice is easier if you have never used a command line; Ghostscript is faster if you convert files regularly.

Converting with online tools

Several free websites will convert your PDF version without installing software. ILovePDF, CloudConvert, and Zamzar all offer PDF version conversion. Upload your file, select version 1.4 or higher from the options, and read the result.

The trade-off is privacy: your file travels to someone else's server. If your PDF contains sensitive information, this may not be the right choice. Read the site's privacy policy to see how long they keep uploaded files. Most delete them within hours, but some keep them longer.

Online converters work quickly for small files (under 50 MB) but may time out or fail on very large PDFs. They also sometimes strip interactive elements like form fields or buttons, so check the result carefully.

What to do if conversion fails or produces errors

If a tool refuses to convert your PDF or the result looks wrong, try a different method. Some PDFs have unusual encoding or embedded fonts that one tool handles better than another. If LibreOffice fails, try Ghostscript. If an online tool times out, use desktop software instead.

If the converted file is much larger than the original, the tool may have added uncompressed images or removed compression. This is usually harmless but wastes storage space. Try a different tool or accept the larger file size.

If interactive elements (forms, buttons, links) disappear after conversion, the tool may not support them. Adobe Acrobat is most reliable for preserving these features. If you need them intact, use Acrobat or contact the PDF's creator for a version-1.4 copy.

Verifying the conversion worked

After converting, always check the new file's properties to confirm the version changed. Open the converted PDF and go to File > Properties (or Tools > Show Inspector on Mac). Look at the PDF Version field and verify it now shows 1.4 or higher.

Also open the file in your usual PDF reader to make sure it looks correct. Scroll through a few pages, check that images display properly, and test any links or form fields if the PDF has them. If something looks wrong, try converting again with a different tool.

Keep both the original and converted files for at least a few days until you confirm the new one works everywhere you need it to.

Frequently Asked Questions

Will converting my PDF make it smaller or larger?

Usually smaller, because version 1.4 and higher support better compression. However, some tools may produce a slightly larger file if they re-encode images or remove existing compression. Check the file size before and after; if it grew significantly, try a different conversion tool.

Can I convert a PDF that is password-protected?

If the PDF is only protected from printing or copying (not from opening), most tools will convert it without trouble. If it requires a password to open, you must enter the password in the conversion tool first. Some online converters cannot handle password-protected files at all; desktop software like Ghostscript or Acrobat usually can.

Does converting change the content or appearance of my PDF?

No. The text, images, and layout stay exactly the same. Only the internal file structure changes. The one exception is interactive elements like form fields or buttons — some conversion tools may lose these, so check the result carefully if your PDF has them.

What is the difference between versions 1.4, 1.5, 1.6, and 1.7?

Each newer version added small features and improvements, but for most everyday use, they are interchangeable. Version 1.4 is the oldest still widely supported. If you need version 1.4 specifically, choose that; if the tool only offers 1.7, that is fine too. Newer is always compatible with older software.

Do I need to convert if I am just reading the PDF on my computer?

No. Modern PDF readers open any version without problems. Convert only if a tool or service specifically asks for version 1.4 or higher, or if you plan to add interactive features that require a newer version.