Compress PDF to 1MB on Mac: The Preset Ladder That Works

Compress at Medium, look at the file size, and move to a lower preset only if the file is still over 1 MB. A preset is a ceiling on how many pixels each embedded image keeps, plus a JPEG quality, so size depends on what is inside the file.

Smol’s five PDF presets cap the long edge of every embedded image at 600, 900, 1200, 1800 and 2400 pixels for Tiny, Small, Medium, Large and Original, with JPEG quality of roughly 25, 45, 60, 75 and 88. They are pixel caps, not DPI targets, so the effective resolution depends on page size. “Original” is not lossless: it re-encodes and resamples above 2,400 pixels. Our explainer on what each PDF preset does walks through it with measured output.

Because Smol sets pixels and quality, not output bytes, it cannot promise a file lands under 1 MB. You check the result. The honest version of this task is a short loop: compress, check, step down.

Limits run from 2 MB to 50 MB depending on who is asking. The table shows the ones we opened on 11 October 2026, each with its own source. Limits change, so read the portal’s current page before you rely on a number.

If a form does not state its limit, pick the nearest tier in the first table on this page (500 KB, 1 MB, 2 MB or 5 MB) and check the result. If you are stuck on a visa form, the visa and immigration page goes deeper on the portals.

Medium is the best first try for 1 MB, and Small or Tiny for 500 KB. We measured all five presets on three files that are big for different reasons, in our upload-limit tests of 26 September 2026. These are three files, not a promise for yours.

Read it against your limit. Under 1 MB, Medium cleared all three, and Large cleared two of them. Under 500 KB, Medium cleared all three but Large cleared none. Under 2 MB, every preset but Original on the design export worked, and every file came in under 5 MB even at Original. The test files held photographs and scanned pages, which is why they shrank so much.

What if you need a PDF under 5MB and want the best quality?

Start at Original and step down only if needed. Original at 2,400 pixels keeps the most detail but still re-encodes, so keep the source file. Check the result either way.

Compress at one preset, check the size, and repeat at the next preset down until the file fits with room to spare. It takes a minute per round, and the first copy stays beside the source.

1. 1

   Note the limit and your target

   Write down the portal’s cap and multiply by 0.7. For 1 MB that is about 700 KB.
2. 2

   Drop the PDF into Smol and pick Medium

   Drag the file into the window, choose the Medium PDF preset, and run the compression. By default, Smol writes a copy next to the original with a _compressed suffix.
3. 3

   Check the size in Finder

   Select the copy and press Command-I. If it is under your target, go to step 5. If not, compress the original again at Small.
4. 4

   Step down if needed

   Try Small, then Tiny. If Tiny is still over, the file is mostly something a preset cannot shrink, so see the wrong-tool section below.
5. 5

   Read the result before you upload

   Open the smallest copy that fits, zoom to 100%, and read the fine print, signatures and numbers. If a figure is hard to read, go one preset up and accept a slightly bigger file.

Several PDFs at once? Drop the whole folder in. Our guide to batch compressing PDFs on a Mac covers it, and a scan needs extra care, which compressing a scanned PDF without killing OCR explains. Smol does not OCR, edit, sign, merge or split PDFs.

The free options are Preview and Ghostscript in Terminal; the rest are paid apps or websites that take your file. Each is fine for some files.

For a one-off, try Preview first because it costs nothing. If the result is still over, or looks soft, Smol’s ladder gives you four more steps. Our five-method test of PDF compression on a Mac has the full comparison, and why Preview’s Reduce File Size can ruin PDFs explains the downside.

Smol is the wrong tool when the PDF is mostly text, when you need an exact byte count, or when you need to change the document rather than shrink it. Here are the specific cases.

• Text-only or vector PDFs. A preset only shrinks images. In our tests, Preview made a three-page, 87,788-byte text PDF 24.2% larger, and some generators produce files that compress by almost nothing. Smol keeps the original if a compress would make a file larger, but you may still be stuck.
• A hard byte target. If a form needs exactly under 1,000,000 bytes with no margin, expect to run the ladder and check. Smol will not guarantee a size.
• Editing, signing, merging or splitting. If a 40-page file must become three files of under 1 MB, you need a PDF editor to split it first.
• Scans that need searchable text. Smol does not OCR. Run OCR with another tool first, then compress.
• Windows or Linux. Smol is macOS only.