or drop a file anywhere here
Files other than PDF are converted first. Signing in raises the size limit.
To compress a PDF, open it here, pick Light, Recommended or Strong and press Compress. The panel shows the current size and an estimate for each level before you run. The smaller file then replaces the open one, and a message shows the size before and after. If you do not like the result, press Undo. Recommended is selected when the panel opens. This page is for anyone whose PDF is refused by a mailbox, an upload form or a chat because it is too large, and who wants a smaller file without installing anything. In our test, a 4.7 MB photo report came out at 367.5 kB with Recommended and its text stayed selectable. How much your file shrinks depends on what is inside it, and there is no box for a target size. You can compress and download without an account, in the browser on a Mac, an iPhone, an Android phone or a PC.
photo-report.pdf, our own 4-page A4 test PDF with four JPEG photos and selectable text, compressed on indox.org
Light is labeled No quality loss, Recommended is Good quality for screen and email, and Strong is Much smaller, softer images. They run at levels 3, 5 and 8 on a scale of 1 to 9. Recommended is selected when the panel opens.
Choose Custom level… and a slider from 1 to 9 appears, with your number beside it. A higher number gives a smaller file, and 9 is the smallest. Use it to reduce PDF size a step at a time.
The panel says how big the file is now and estimates the size at each level before you run. When a run finishes, a message shows the old size, the new size and the percentage saved. In our test the estimates were cautious: Recommended was estimated at about 706.5 kB and the result was 367.5 kB.
Compress swaps the smaller file into the editor, and the message has an Undo button. Your other edits are kept, and the copy on your device is never touched.
Switch on Also make text searchable (OCR), choose the languages and the button becomes Compress and make searchable. This option needs an account, and a signed-out visitor gets a sign-up dialog when it runs.
The tool works in a browser, so there is nothing to install on a Mac, an iPhone, an iPad or an Android phone.
| You want to | Choose | Check after |
|---|---|---|
| Email a text-heavy report | Recommended | Compare the new size with the mailbox limit. Personal Gmail accounts allow 25 MB per message. |
| Keep a contract or invoice sharp | Light | Compare the two sizes. Light is labeled No quality loss, so the saving may be small. |
| Send a photo-heavy brochure or a scan over a slow connection | Strong | Look at photos, stamps and small print at 100%. |
| Get the smallest file the panel can make | Custom level… at 9 | Read the pages again. If the file is still too big, cut it with Split PDF. |
Put a PDF in the upload area by choosing a file, dropping it or using From URL. It opens in the editor with the Compress panel.
Pick Light, Recommended or Strong. For your own number, choose Custom level… and move the slider.
The button reads Compressing… while the job runs. When it ends, a message shows the size before and after.
Wait for the message that shows both sizes. In our test the status read Done for a moment before the compressed file replaced the open one, and a download in that moment saved the original. Then compare the sizes and look over the pages. Press Undo if the result is not what you want, or choose Download PDF to save it.
This PDF compressor gives you three presets and a slider from 1 to 9. You see the size before and after on screen, and Undo is one press away if the result is worse than the original. Compressing and downloading need no account. A measured run further down shows the sizes, what stayed the same and what changed, with a before and after slider.
| What you see | Why | What to do |
|---|---|---|
| The file is barely smaller | It is mostly text, or it was already optimized | Try Strong or Custom level… at 9. To drop pages you do not need, use Remove Pages. |
| The new size is the same or bigger | The editor does not check that the result is smaller, and it replaces the open file anyway | Press Undo in the message, then try another level or keep the original. |
| Download PDF saved the original file | The status read Done before the compressed file replaced the open one, and the download came from the old file | Wait for the message that shows both sizes, then choose Download PDF. Check that the size matches the message. |
| The result is smaller than the estimate | The estimates are cautious. In our test Recommended was estimated at about 706.5 kB and gave 367.5 kB | Read the size in the message after the run, not the estimate. |
| A warning says Compression didn’t run, your file is unchanged | The compression step failed and the job finished with your file as it was | Press Compress again. If the file may be damaged, try Repair PDF first. |
| Photos or scans look soft | Strong and high Custom levels lower image quality | Press Undo and pick Light or Recommended. |
| Compress and make searchable opens a sign-up dialog | The OCR option needs an account | Sign up, or switch the OCR option off to compress without one. |
| It is still over the size limit at level 9 | The content itself is too big for one file | Cut it into parts with Split PDF. |
| Method | What it changes | Text | Pick it when |
|---|---|---|---|
| Light (level 3) | Re-packs the file's streams and leaves images as they are (levels 1 to 3) | Not touched | The pages must stay as they are and a small saving is enough |
| Recommended (level 5) | Re-packs, then re-encodes and downsizes images. In our test the photos went from 305 to 207 dpi | Stayed selectable in our test | A PDF with photos or scans has to fit a mailbox or upload form |
| Strong (level 8) | Also rewrites images at 100 dpi for colour, per the Stirling-PDF source | We did not test a downloaded file | Size matters more than sharp photos |
| Custom level 9 | Rewrites colour images at 72 dpi, the smallest the panel makes, per the Stirling-PDF source | We did not test a downloaded file | Every other level was still too big |
| Remove Images | Drops the pictures | Stays | The pictures are not needed |
| Remove Pages or Split PDF | Makes the file smaller by dropping or separating pages | Stays | Compression alone is not enough |
| OCR PDF | Adds a text layer to a scan, and the compress panel warns the file can grow | Becomes selectable | A scan has to be searchable, not smaller |
A mail provider rejects a PDF over its limit. Try Recommended first and Strong if it is still too big.
Job, visa and school portals cap each upload. Compress the scan of your documents until the portal accepts it.
A report full of charts and screenshots is slow to pass around. A smaller copy posts in chat and downloads on mobile data more easily.
Facts checked on November 4, 2026
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Add your PDF, pick Light, Recommended or Strong in the Compress panel and press Compress. The smaller file replaces the open one, and Download PDF saves it. You can compress without an account.
Compress it with Recommended, then compare the new size with your mailbox limit. Personal Gmail accounts allow 25 MB per message, according to Google's help page. If the file is still too big, try Strong, or cut it into parts with Split PDF.
It can. In our test, Recommended re-encoded the four photos in a PDF from 1800 by 1200 to 1224 by 816 pixels, which is 305 to 207 dpi at the printed size, and the result looked only slightly softer in the before and after slider on this page. Text, page count and fonts did not change. Strong goes further and its label says softer images, but we did not download or measure that output. Light is labeled No quality loss, and we did not test it. To compress without losing quality, start with Light, compare the sizes, zoom in on the pages that matter and press Undo if you see a loss.
In our test, yes at Recommended. We compressed a four-page PDF with Helvetica text and four photos. Afterwards it still had 4 pages, 556 characters on each page, the same fonts, and a test phrase was found 24 times out of 24. We did not test a Strong output or a scanned page, which has no text layer unless OCR was run.
Some PDFs have little left to squeeze, such as a file that is mostly text or one that was already optimized. The editor does not check that the result is smaller, so it can show the same size or a bigger one. Try Strong or Custom level… at 9, and press Undo if the new file is no better.
Start with Recommended, which is selected when the panel opens. Use Light when the pages must stay sharp and Strong when size matters most. Custom level… gives you every number from 1 to 9.
A scan is a stack of page pictures, so the image quality setting decides the size. Strong gives the smallest file at lower image quality. Switch on Also make text searchable (OCR) if you want selectable text too, which needs an account. The panel warns that OCR can make the file larger.
No. The panel has levels and no size box, so a PDF under 2 MB or any other cap takes trial and error. Raise the level one step at a time and read the new size after each run. In our test one Recommended run took a 4.7 MB photo PDF to 367.5 kB, but a PDF that is mostly text may barely change. If level 9 is still over the cap, cut the file with Split PDF.
Yes. The tool works in your browser, so there is no app to install on a Mac, an iPhone, an iPad or an Android phone. Open this page, add the PDF and press Compress.
No. Compressing and downloading work without signing in. Only the OCR option, Also make text searchable (OCR), needs an account.