In our best PDF compressor comparison, we tested 7 tools on the same 15.59MB file, and results ranged from a 76% cut to almost no change at all.

Based on our test, one of the best PDF compressors in 2026 is PDFgear, which took our 15.59MB test file down to 3.7MB, which is a 76% reduction, with no visible quality loss and no account required.

We ran the same file through six other tools: Adobe Acrobat, Smallpdf, Sejda, iLovePDF, PDF24, and pdf.net, measuring processing time and checking the results at 150% zoom. Compression results varied, whereas free-tier limits, account requirements, and processing time varied even more.

With that said, let’s see what we found for each tool, plus what actually matters when you're picking one.

PDFgear compressed our 15.59MB test file to 3.7MB (76% smaller) for free, with no visible quality loss and no account required.

pdf.net was the fastest tool we tested, compressing the same file in 5–8 seconds at every quality level, though its compression feature requires a paid account.

Smallpdf was the weakest performer: its free tier barely changed the file size, and its paid desktop app badly underperformed its own paid web results.

Every tested tool kept text selectable after compression. Visible quality loss only showed up on smaller embedded images at 150% zoom, and only on two of the seven tools.

Free-tier limits vary widely, from Sejda's 3 tasks per hour to PDF24 and PDFgear, where we didn't observe any limit at all.

Choosing the best PDF compressor online comes down to 

 This is what most people mean by "how much smaller did it get." In our testing, results ranged from a 76% reduction to almost no change on the same file.

 noticeably will recompress images at a lower bitrate rather than downsampling resolution outright. A PDF's fixed, image-heavy structure is part of why that trade-off exists in the first place. We checked every tool's output at 150% zoom to catch it.

 This saves real time if you're compressing more than a couple of files at once, and it's worth checking before you commit to a tool, especially if you need to merge several PDFs into one before compressing.

 These decide whether a tool can even open your file. Gmail, for instance, 

, so compression ratio matters most if you're trying to squeeze under a cap like that. However, if you'd rather skip compression entirely, there are other ways to 

 Compressing a PDF online means uploading it to someone else's server, even briefly. 

 is a good starting point if the file is sensitive, and it's worth checking 

 before you upload anything financial or legal.

 Costs ranged from completely free to a monthly subscription in our test, and a few tools only charge once you go past their basic compression level.

7 Best Tools for Compressing PDFs in 2026

, both the web and desktop versions where a tool offered one. We measured compression ratio, processing time, and visible quality loss at 150% zoom, then ranked the seven by what the results actually showed, not by brand size.

PDFgear delivered the best compression of any tool we tested, cutting our 15.59MB file to 3.7MB (76% reduction) with its 

 setting in 12.31 seconds, with no visible quality loss and no account required.

 compression pushed the same file down further, to 2.5MB (an 84% reduction), in 11.13 seconds. The 

 still, compressing the file to 7.68MB (50.7% smaller) in just 3.45 seconds, though its 

 compression settings produced the exact same output in our test, which is a bug worth knowing about before you rely on those specific settings.

 was the fastest tool, compressing the file in 5–8 seconds at every one of its 

, with no visible quality loss at any setting.

 level took the 15.59MB file to 9.37MB (a 40% reduction); 

 reached 14.19MB (9% smaller). Since it's browser-based, the workflow is: upload, choose a level, compress, and download to your device.

Upload your file and pick a compression level — no software to install.

Compress PDFs in Seconds, Right in Your Browser

's desktop app compressed our file to 11.74MB (a 24.7% reduction) in 11 seconds using 

, but reaching the best result took extra effort.

 brought the same file down to 5.07MB (a 67% reduction), but 

 alone didn't get there on the first attempt, an inconsistency worth knowing about. The desktop apps also handled batch compression, processing multiple files in about 18 seconds in our test.

The web version compressed the file to 14.1MB (9.6% smaller) at the 

 setting in 25 seconds, notably slower than its own estimate suggested (Adobe's tool estimated 9.8MB). It also refused to compress an already-compressed file, returning an error instead.

 setting took our file from 15.59MB to 12.75MB (19% reduction) in 8.56 seconds on the web, with no visible quality loss. The 

However, it’s worth noting that the web version's compression labels didn't behave as expected in our test:

 produced a larger 14.64MB file, the opposite of what those labels promise. The desktop app didn't have this problem.

 setting compressed our file to 13.67MB (a 12.3% reduction) in 28.5 seconds, the 

 settings scaled exactly as labeled: Good produced 14.15MB at 9.2% smaller, and Best produced 14.37MB at 7.8% smaller.

Also, Sejda was the only tool in our test where we saw 

 on the smaller-dimension photo at 150% zoom. The desktop app matched the 

PDF24 compressed our file to 14.07MB (a 9.8% reduction) in 11.78 seconds on the web using its preset 144 DPI, 75% quality settings, which is modest compared to PDFgear's automatic result.

For anyone specifically after the best PDF compressor software for PC, PDF24's 

desktop app compressed the same file in about half the time of the web tool

visible quality loss on a smaller embedded photo

 at 150% zoom where the web version didn't.

PDF24's web tool also offers the most granular manual controls of any tool we tested, including DPI, image quality percentage, thumbnail removal, and font subsetting, all with no usage limit observed. There's no paid tier since PDF24 is

free web tier barely changed the file size

, cutting 15.59MB down to just 15.3MB, a 1.9% reduction, in 11.52 seconds. The free desktop version performed worse; it made the file 0.1% larger.

 reached 6.1MB (60.9% smaller) with no visible quality loss. On the other hand, the paid desktop app's 

 setting only reached 14.97MB, a 4.0% reduction on the identical file, a major gap between two products with the same name and the same price.

free web tier locks users out after around four downloads

, showing a wait timer instead, though we didn't hit any file-size limit on desktop.

Compression results vary far more between PDF tools than most people expect. The gap between the best and worst performer in our test was the difference between barely noticeable and dramatic. The right pick comes down to what you're optimizing for: maximum size reduction, speed, security, or just not wanting to install anything.

Free-tier limits are worth checking as closely as compression ratio, since a task cap or download lock can matter more day-to-day than a few extra percentage points of savings. Whichever PDF compressor you choose, testing it on your own file and checking the result at full zoom beats trusting a vendor's marketing claim.

A PDF can typically be compressed anywhere from 10% to 80%, depending on its content and the tool used. In our test, results on the identical 15.59MB file ranged from a 1.9% to a 76% reduction.

#2. Does compressing a PDF reduce quality?

 can reduce quality, but it doesn't have to. In our testing, five of the seven tools showed no visible quality loss at 150% zoom; only Sejda and PDF24's desktop app showed slight degradation on a smaller embedded photo.

#3. Can I compress a password-protected PDF?

Compressing a password-protected PDF usually requires unlocking it first, since most compressors can't process encrypted files directly. 

 before compressing, then reapplying protection afterward, is the standard workaround.

#4. What is the difference between lossless and lossy PDF compression?

Lossless PDF compression shrinks file size without discarding data, usually by cleaning up structure or fonts. Lossy compression reduces image quality to save more space.

Best PDF Compressor in 2026: 7 Tools Tested, One Cut Size 76%

Types of PDF include PDF/A, PDF/X, fillable PDFs, and more, and knowing which one to use can help you avoid document errors.

"Type of PDF" actually means two different things, and mixing them up is why this gets confusing. Some types like standard, scanned, fillable, and searchable describe what's 

 the file. Others, such as PDF/A, PDF/X, PDF/E, PDF/VT, and PDF/UA, are ISO-certified format standards that describe rules the file 

, for things like archiving, printing, or accessibility.

Using the wrong type in the wrong tool can cause missing fonts, forms that will not fill in, or documents that print incorrectly. This guide breaks down the most common types of PDF documents, explains when to use each one, and shows you how to check which type you already have.

PDF types fall into two groups: content types that describe what's in the file, and ISO formats (PDF/A, PDF/X, PDF/E, PDF/VT, PDF/UA) that describe rules it follows; a file can belong to both at once.

Standard PDFs work fine for everyday sharing, but specialized types like PDF/A, PDF/X, and PDF/UA exist for archiving, printing, and accessibility.

PDF/A locks in a file's appearance for long-term storage, while PDF/X is built for commercial printing presses.

Fillable and interactive PDFs contain form fields you can click and type into, unlike scanned or flattened PDFs.

You can identify a PDF's type by checking whether you can select text, search the file, or find form fields.

An online editor lets you convert, edit, or fill out nearly any type of PDF without installing special software.

multiple versions that follow the same base format but add rules for a specific use

, such as for printing, archiving, accessibility, filling out forms, etc.

These types fall into two different groups, but they're not mutually exclusive since a single PDF can belong to both.

, which are formal specifications a file either does or doesn't conform to (PDF/A, PDF/X, PDF/E, PDF/VT, PDF/UA). The second covers 

 or what it contains (standard, scanned, fillable, searchable).

A scanned PDF, for example, could also be PDF/A compliant, and a fillable PDF could also be tagged for PDF/UA accessibility. That said, here are the nine types of PDF formats you are most likely to come across, starting with the everyday content types.

the most common of the many types of PDF formats you will come across

. It is a document saved in the original 

, without any embedded archival or print standard attached. These PDFs preserve fonts, images, and layout across devices, which is why they became the default choice for resumes, contracts, and reports.

 Universal compatibility and small file sizes.

 Limited accessibility support and no guarantee that the file will look identical decades from now.

 where formatting matters more than long-term preservation. If you need to make changes later, you can edit text directly in a standard PDF using a 

created by photographing or scanning a paper document

, which turns each page into an image rather than searchable text. This means you cannot select, copy, or search the words on the page unless the file goes through additional processing.

 in its original form, and often larger in file size than a text-based PDF. Editing becomes possible once OCR is applied.

If you need to work with the content, you can convert a scanned PDF into an editable Word document, or add text over the image directly if you just need to fill in a few fields.

, contains form fields you can click on and type into directly, such as 

, drop-down menus, and check boxes. Unlike a flat document, the fields stay editable no matter how many times someone fills them out and clears them again.

 No printing or handwriting required, faster data collection, and works well for repeat use.

 Fields can break if the PDF is flattened or opened in an unsupported viewer.

applications, intake forms, and contracts

 instead of building one from a blank page.

looks like a scanned document but has an invisible text layer added underneath

, usually through optical character recognition, or OCR. This lets you search, copy, and 

 even though the page still displays as an image.

 Combines the reliability of a scanned image with the convenience of searchable text.

 OCR accuracy depends on scan quality, so poor originals can produce errors.

Libraries, courts, and research institutions favor this type for digitized records, and 

federal guidance on scanned document formats

 recommends OCR processing for records intended to remain useful long-term.

a specialized version of PDF built for long-term archiving

. It locks fonts, colors, and layout inside the file itself, so the document looks the same in twenty years as it does today, regardless of which software opens it. Government agencies, law firms, and libraries rely on PDF/A because it does not depend on external files or 

 Guaranteed visual consistency, self-contained files, and wide institutional support.

 Most PDF/A versions cannot contain audio, video, or encryption, so it is not ideal for interactive content (PDF/A-3 is the exception, allowing embedded files).

, which defines exactly how a PDF must be structured to qualify. If your organization needs to submit archival records or court filings, this is usually the required format.

designed for commercial printing and prepress work

. It restricts the file to elements a printing press can handle correctly, such as embedded fonts and specific color profiles, which prevents surprises when a document goes to print.

 Consistent color reproduction, fewer printing errors, and industry-standard for print shops.

 Not suited for on-screen viewing or digital distribution, and 

Graphic designers and print vendors use PDF/X for 

brochures, magazines, and packaging artwork

. Before sending a file to print, it often helps to 

 first, since press-ready files with embedded fonts and high-resolution images can get large without adding print quality.

supports engineering and technical documentation, including CAD drawings, 3D models, and multimedia annotations

. It was created for industries like construction, manufacturing, and aerospace, where a single document might combine blueprints, measurements, and markup notes.

 Supports rich technical content and interactive 3D.

 Less common, so not every viewer supports every feature, and adoption outside engineering fields is limited.

If your team works with technical drawings, you may need to 

, such as separate drawings or revision sheets, into a single set before sharing them with contractors or reviewers.

, and it handles print jobs where each copy contains different data, like personalized mailers, invoices, or statements. The format bundles the shared design elements once and layers in the variable data for each recipient, which speeds up large print runs.

 Efficient for high-volume, personalized printing.

 A niche format mainly used by print production software, not everyday 

Banks, insurance companies, and marketing firms use this option for mass communications where every document needs a name, account number, or address swapped in.

, ensures a PDF works correctly with screen readers and other assistive technology. It requires tagged headings, alt text for images, and a logical reading order so people with visual or cognitive disabilities can navigate the document.

 Legally required for many government and public-facing documents.

 Takes more effort to create correctly, since tagging has to be done manually or checked carefully.

 to meet these requirements, and any organization that publishes public documents should aim for the same standard.

You will know which type of PDF you have if you check for this handful of simple details:

Check whether you can select/highlight text. 

Open the file and try to highlight a sentence. If your cursor selects individual words, you have a standard, searchable, or fillable PDF. If 

 on Mac) and search for a word you know appears in the file. A match confirms the PDF has a text layer, even if it looks like a scan.

Look for boxes, checkboxes, or dropdowns you can click into. If you see blue-gray highlighted fields when you click inside the document, it is a fillable or 

Check the document properties or standards. 

Open the file's properties panel, usually under a menu labeled 

. Some viewers list the PDF version or standard, such as PDF/A-2b.

A signed PDF usually shows a signature panel or a small ribbon icon near the top of the viewer. If you plan to add your own approval, you can 

 directly in an online editor instead of printing the page to sign it by hand.

Work with standard, scanned, or fillable PDFs in one browser-based editor.

Edit, Convert, and Sign Any Type of PDF

Being aware of all different types of PDF files helps you pick the right one for the job, whether that means archiving a legal record, sending a print-ready design, or collecting signatures on a form.

Most everyday tasks only call for a standard PDF, but knowing when a specialized format like PDF/A or PDF/UA applies can save you from rejected filings or accessibility complaints down the road. Whichever type of PDF you are working with, 

 can help you view, convert, or fill it out without switching between separate programs!

, which is typically used for everyday documents like resumes, 

, and reports. It has no embedded archival or print standard attached, and that makes it the default format most PDF readers and editors expect.

; the right choice depends on your purpose. For instance, PDF/A suits long-term archiving, PDF/X suits professional printing, and a standard PDF works fine for routine sharing and everyday documents.

best type of PDF for professional printing

, since it embeds fonts and enforces color profiles that printing presses require. For basic home or office printing, a standard PDF works without any issues.

, including standard and fillable PDFs, using an online editor. Scanned PDFs can't be edited directly since the text is part of an image, but running OCR first converts them into an editable, searchable file. PDF/A files resist edits by design, since the format exists to keep documents unchanged for archival purposes.

9 Types of PDF Files and When You Should Use Each One

Learn how to scan a PDF on iPhone using Notes, Files, or your camera, then edit, compress, and share the finished document easily.

To scan a PDF on iPhone without downloading anything extra, open the Notes app, the Files app, or Preview app, capture the document, and save it as a PDF. Digital paperwork is easier to search, store, and share than paper, and a scanned PDF keeps its layout on any device.

Apple added scanners into iOS years ago, so no separate app is required. That said, this guide covers three simple scanning methods, converting existing photos to PDF, and editing the finished file.

Notes, Files, and Preview apps can all scan a PDF on iPhone without a third-party app.

The Files app scanner saves straight to iCloud Drive or a folder of your choice, while Notes is quicker for a single, one-off page.

Preview lets you scan documents and work with the resulting PDF in the same app.

You can convert existing photos into a PDF instead of rescanning the original document.

pdf.net lets you edit, compress, or e-sign a scanned PDF once it's on your phone.

Even lighting, a flat surface, and a steady hand make the biggest difference in scan quality.

How to Scan a PDF on iPhone in 3 Simple Ways

There are three ways to scan a PDF on an iPhone, and none of them require software installation: the 

#1. How to Scan a PDF on iPhone Using Notes

Scanning a PDF on an iPhone with Notes is the 

, since the scan is inside a note where you can 

scanner straightens and crops the page automatically

Here's how to scan a document with an iPhone using Notes:

 and select an existing note or create a new one.


Tap the attachment button (the camera icon), then choose Scan Documents.

Hold your iPhone over the document. Auto mode captures the page on its own, or you can tap the shutter button manually.


Auto mode captures the page on its own, or you can tap the shutter button manually.

Drag the corners if the crop looks off, then tap 

Drag the corners if the crop looks off, then tap Keep Scan.

 icon from the note and choose where it should go.

#2. How to Scan a PDF on iPhone with Files App

better choice when you want the finished PDF to land in a specific folder

. If you've been searching for how to scan a PDF file on an iPhone and have it organized the moment it saves, this is the method to use.

Here's how to scan a PDF file on iPhone with Files:

 and go to the folder where you want to save the scan.


How to Scan a PDF on iPhone with Files App

 button (three dots) in the top-right corner.


Tap the More button (three dots) in the top-right corner.

Capture each page using Auto mode or the manual shutter button.

Adjust the corners, tap Keep Scan, and repeat for multiple pages.

 in that folder immediately, and you can 

#3. How to Scan a PDF on iPhone with Preview

If you want a dedicated place to scan and work with PDFs, Apple's Preview app puts 

document scanning and PDF tools in the same place

. You can scan a document, adjust the pages, and then 

To scan a PDF on iPhone with Preview, follow these steps:

How to Scan a PDF on iPhone with Preview App

Hold your iPhone over the document. Auto mode captures automatically, or tap 

Hold your iPhone over the document. Auto mode captures automatically.

if needed, then repeat for additional pages.


Blog

Best PDF Compressor in 2026: 7 Tools Tested, One Cut Size 76%

9 Types of PDF Files and When You Should Use Each One

How to Scan a PDF on Your iPhone with No Software Installation

PDF Won’t Compress: Causes & How To Solve the Issue

How to Convert JPGs to PDF on Mac, Android, and iPhone

How to Edit PDF Metadata: 3 Free Methods Explained

How to Encrypt a PDF and Keep Your Documents Secure

Chat With Your PDF: 23+ Copy-Paste Prompts That Get Results

What Is a Shared Space in pdf.net? A Guide to PDF Teamwork

8 Best PDF Password Removers Online in 2026: Tested & Compared