How to reduce PDF size under 100KB

Sometimes, all you need is to send a file—but the upload limit says no. Whether you're submitting a form online, uploading to a legal portal, or emailing a document, size limits can be frustrating. If you're trying to get your PDF under 100KB, there's a surprisingly simple way to do it: Split by Size.

Let’s walk through how this works, when to use it, and why it’s so handy when you’re up against strict file size limits.

Key takeaways

• You can reduce PDF size by splitting it into smaller parts using the "Split by Size" feature
• It’s perfect for meeting upload limits like 100KB, especially for legal or government platforms
• You set the size (like 100KB), and the tool does the work—no guessing or manual compression needed
• This method is useful when compression isn’t enough or when you only need to send a portion of a document

How to use Split by Size to reduce PDF below 100KB

Here’s a step-by-step guide to getting it done:

Why you might need to shrink a PDF under 100KB

Some platforms just weren’t built with today’s file sizes in mind. They often set strict upload limits that can make even a basic PDF too large to submit. Here are a few common situations where you’ll likely run into that 100KB cap—and why knowing how to shrink your file can save you time and frustration.

Government portals

Many government websites still operate with older systems that limit upload sizes. Whether you're applying for permits, submitting identification, or uploading tax documents, you're often asked to keep your files small.

Visa applications

Embassy and immigration portals typically request very specific file formats and sizes. If you’re applying for a visa, you’ve probably seen a max size listed—and it’s often under 100KB. A rejected upload can mean delays, so getting it right matters.

Court document submissions

Legal portals often restrict file sizes to ensure fast processing and compatibility across systems. If you’re submitting evidence or forms, having your documents within the accepted size range is key to avoiding resubmissions.

Older websites or email services

Some older platforms—and even a few email providers—have file size limits that haven’t changed in years. If you're trying to send something important and it keeps bouncing back, the file size is usually the culprit.

What is "Split by Size"?

The "Split by Size" feature with the Split PDF tool does exactly what it sounds like.

You set a target file size—like 100KB—and the tool splits your PDF into multiple smaller files, each one staying under that limit.

Here's why it’s useful:

• You control the limit: Pick any size in KB or MB.
• No quality loss: Unlike compression, splitting doesn't degrade image or text quality.
• Keeps formatting intact: Each split file looks just like the original—just shorter.
• Instant results: No trial and error.

When is splitting better than compressing?

Compression is usually the first thing people try when they need to shrink a PDF. It’s quick, doesn’t change the structure of your document, and often gets the job done. But when the file still won’t meet strict limits—like staying under 100KB—compression might not be enough.

That’s when Split by Size becomes the better option.

Your original file is large

If your PDF is more than 50 MB, even aggressive compression might not bring it down far enough. In these cases, breaking the file into smaller pieces is often the only realistic way to meet the limit.

You only need to share a portion

Sometimes you don’t need to send the whole document. Maybe it’s just a few pages that are relevant for a form, an application, or a review. Splitting lets you isolate the section you need, without shrinking the entire file.

Compression affects quality

When you compress a file too much, it can start to look blurry or distorted—especially if it includes images or scanned pages. Splitting avoids this issue by keeping the original quality intact.

You want precise control

Compression doesn’t always give predictable results. One setting might get you close to your goal, but not quite. With splitting, you set the file size limit yourself—and the tool delivers files that meet it exactly.

A few things to keep in mind

While Split by Size is a powerful tool, there are a couple of practical details worth considering before you dive in. These tips can help you get the best results and avoid surprises when working with your PDF.

• Split by size works best on documents with lots of pages. If your PDF is only one or two pages, consider compressing instead.
• If your file contains mostly images, splitting may still result in larger chunks—try compressing first, then splitting.
• Always check the content after splitting to make sure the information is complete and readable.

Practical, easy, and reliable

Trying to get a PDF under 100KB doesn’t have to be a headache. Whether it’s a stubborn upload form or a deadline with strict rules, the "Split by Size" feature gives you control without hassle.

Need to shrink your PDF fast without losing quality? Try splitting by size today!

Split your PDF now