Compress Pdf
Upload your PDF and compress it to your desired file size in seconds.
or drag and drop (max 50 MB)
Size:
Compression Settings
Processing...
Compression Complete!
How to Compress a PDF File
Reduce your PDF's file size in seconds — no software installation needed, no sign-up required.
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Upload Your PDF
Click the "Select PDF File" button or drag and drop your PDF onto the upload area. The tool accepts files up to 50 MB. Once the file is loaded, its name and current size are displayed below the upload zone so you can confirm the correct document is selected before proceeding.
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Choose a Compression Level
Use the Compression Level slider to set how aggressively the file should be reduced. Lower values prioritise quality and produce a moderately smaller file. Higher values push for maximum size reduction at the expense of some visual fidelity. For most everyday uses, the default Standard setting delivers the best balance. See the settings reference table below for guidance on each level.
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Set Resolution (DPI)
The DPI setting controls how images embedded in the PDF are resampled during compression. Lower DPI values produce significantly smaller files but reduce the sharpness of photos and graphics. If your PDF is mostly text, DPI has less impact. If it contains many images, choosing a lower DPI is the most effective way to shrink the file size. The default of 200 DPI is suitable for on-screen reading and most office use.
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Choose a Color Mode
Select Color to preserve the original appearance of the document. Choose Grayscale to strip all color information and convert the document to black-and-white tones — this can meaningfully reduce file size for PDFs that don't rely on color for readability, such as text reports, scanned documents, or printed articles.
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Compress and Download
Click the Compress PDF button to begin processing. A progress bar tracks the operation in real time. Once complete, a results panel shows your original file size, the new compressed size, and the percentage of space saved. Click Download Compressed PDF to save the file to your device.
💡 Pro Tips
- PDFs made primarily of text compress less dramatically than image-heavy ones — a text-only report may only shrink by 10–20%, while a photo-filled brochure can shrink by 60–80%.
- If you need the file under a specific size (e.g. a 5 MB email limit), try compressing once at Standard, check the result, and re-compress at a higher level if needed.
- Switching to Grayscale at 72 DPI gives the maximum possible size reduction — ideal when the document only needs to be read on screen.
- For documents you plan to print professionally, use 300 DPI with a low-to-medium compression level to preserve print quality.
- Already-compressed PDFs (e.g. previously exported from Word) may see minimal further reduction — the tool will still process them, but gains will be smaller.
Compression Settings Reference
Understanding each setting helps you make the right trade-off between file size and visual quality.
| Setting | Option | File Size Impact | Best For |
|---|---|---|---|
| Compression Level 1–2 | Light | Minimal reduction (5–15%) | Archival copies where maximum quality must be preserved |
| Compression Level 3–4 | Standard Default | Moderate reduction (20–45%) | Email attachments, shared documents, everyday office files |
| Compression Level 5–6 | Aggressive | High reduction (50–80%) | Web uploads, messaging apps, anywhere a strict size limit applies |
| 72 DPI | Screen viewing | Largest reduction | Digital-only documents viewed on monitors, phones, or tablets |
| 150 DPI | Good quality | Moderate reduction | Internal reports, casual sharing, documents not intended for print |
| 200 DPI | High quality Default | Balanced reduction | General use — suitable for both screen reading and light printing |
| 300 DPI | Print quality | Least reduction | Documents destined for professional or home printing |
| Grayscale | Color mode | Significant reduction | Text-heavy documents, scanned pages, any file where color is unnecessary |
Understanding DPI in PDF Compression
DPI (dots per inch) determines the resolution at which embedded images are stored. It's often the single biggest lever for reducing PDF file size.
Matches standard monitor resolution. Files are very small but images will look soft when zoomed in or printed.
Noticeably sharper than 72 DPI with a moderate file size. A practical choice for shared digital documents.
Clear and readable on all screen sizes. Fine for everyday office printing. A good all-round setting.
The standard for professional printing. Produces the sharpest images at the cost of a larger output file.
Common Use Cases for PDF Compression
Oversized PDFs are one of the most frequent practical problems in digital document workflows.
Email Attachments
Most email providers cap attachments at 10–25 MB. Compress large reports, brochures, or portfolios to stay within limits without splitting the file.
Cloud Storage Quotas
Compress PDFs before uploading to Google Drive, Dropbox, or OneDrive to stay within free tier storage limits across large document libraries.
Government & Portal Submissions
Many official portals (tax filings, visa applications, court submissions) enforce strict file size caps — compress to meet these requirements without losing content.
Website Downloads
Reduce the download size of PDF white papers, catalogues, or brochures hosted on your website so visitors experience faster load and download times.
Mobile Sharing
Compress PDFs before sending over WhatsApp, Telegram, or similar messaging apps which often cap file sizes at 16–100 MB depending on the platform.
Print Shop Uploads
Some online print services have upload size restrictions. Compress at 300 DPI to reduce file size while keeping the resolution sharp enough for professional print output.
Frequently Asked Questions
Clear answers to the most common questions about compressing PDFs.
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Your file is processed to perform the compression and generate the output, but it is not stored, indexed, or shared. No copies of your document are retained after you download the result. The tool is designed for single-use sessions — once you close the page, your file is no longer accessible. It is safe to use for confidential materials such as financial reports, legal documents, medical records, and identity documents.
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The amount of compression achieved depends heavily on the content of your PDF. Image-heavy documents — such as brochures, catalogues, scanned pages, or photo-rich reports — can typically be reduced by 50–80% at aggressive settings. Text-only PDFs, or files that have already been compressed by the software that created them, will see more modest reductions of 5–25%. The results panel after compression shows the exact original and compressed sizes along with the percentage saved, so you can always verify the outcome before downloading.
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Text rendered as vector outlines in a PDF (which is how most word processors, design tools, and modern PDF exporters produce text) is not affected by DPI settings or compression level — it remains perfectly sharp at any zoom level regardless of the settings you choose. Only raster images embedded within the PDF are affected. If your document contains scanned pages where the text is embedded as a photograph rather than as searchable vector characters, lower DPI settings may make that text slightly softer.
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The tool accepts PDF files up to 50 MB. If your file exceeds this limit, you have a few options before uploading: use the PDF Splitter tool on this site to divide the document into smaller sections and compress each one separately, or reduce the file size using another method first (such as re-exporting from the original application at a lower quality). Compressing each half separately and then merging the results with the PDF Merge tool is also a practical workflow for very large files.
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Grayscale mode converts all color information in the document to shades of black and white. This is most useful when the color in the PDF serves no functional purpose — for example, a scanned black-and-white document that was saved in color format, a text report with a colored header, or any document that will only ever be read or printed in black and white. For documents where color is essential to meaning (charts with color-coded data, branded marketing materials, medical imaging), you should keep the Color setting to avoid losing important visual information.
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Yes, you can run a previously compressed PDF through the tool again. However, successive compression yields diminishing returns — once images have already been downsampled and compressed, there is less redundant data to remove in subsequent passes. Re-compressing an already-compressed file at the same settings will typically produce only marginal further reduction, and at very aggressive settings on already-compressed images, you may start to see visible quality degradation without meaningful size savings. If you need a significantly smaller file, try switching to a lower DPI or enabling Grayscale mode in addition to increasing the compression level.
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The compression process focuses on reducing image data and stream sizes within the PDF. Bookmarks (table of contents entries), internal and external hyperlinks, and fillable form fields are generally preserved in the output. However, very aggressive compression at the highest levels may restructure some internal PDF objects in ways that could affect complex interactive elements. For documents containing important interactivity — such as fillable forms or extensive navigation bookmarks — it is recommended to test the output by opening it in a PDF viewer before distributing or submitting it.
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In rare cases, a compressed PDF can end up slightly larger than the source. This typically happens when the original PDF was already highly optimized (for example, exported by a modern application with built-in compression) and the reprocessing overhead — such as re-encoding image streams or restructuring PDF objects — adds more bytes than it removes. If this happens, simply discard the compressed output and keep your original. The original was already as small as practical for its content. You may also try a lower compression level, which sometimes produces better results on already-efficient files.
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Yes. The tool is fully accessible on modern mobile browsers including Safari on iOS and Chrome on Android. You can select a PDF from your device's local storage, Files app, or connected cloud services such as Google Drive or iCloud. Processing time on mobile may be slightly longer for large files due to more limited CPU resources, but the output quality and settings are identical to desktop use. For very large PDFs near the 50 MB limit, a desktop browser is recommended for the most reliable experience.
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The tool is completely free with no account, subscription, or payment required. No watermarks, branding, logos, or metadata are added to the compressed PDF. The output file contains only the original content of your document — nothing is inserted, appended, or modified beyond the compression itself. There are no daily usage limits or restrictions on file types within the supported formats.