How to compress a PDF without uploading it

Shrink a PDF in this browser when the weight is sloppy structure, not a photograph of paper. Folio rewrites the file locally. It does not send the document to a compressor.

Open the compressor If it is a scan

Mail apps, government portals and chat tools still cap attachments. The reflex is to “compress PDF online”, which usually means: upload, wait, download a rasterized cousin of your file, maybe with a watermark if you are not on a plan. Folio’s compressor is narrower. It copies pages into a new PDF and can strip metadata and pack objects. It will not blur a scan into a smaller JPEG for you.

That honesty is the product. If you bring a 40 MB colour scan, the after size will look like the before size — why scans stay heavy. If you bring a 12 MB Word export, Balanced may actually help. Chrome, Edge, Firefox and Safari are supported. JavaScript on. Password-protected files are refused.

Gmail and Outlook numbers, including MIME overhead, live on the email size guide. Chat sends: WhatsApp. Merge is a different tab — compress does not join files. Split if you only need some pages: how to split. This page is the mechanical how-to for the compressor.

What High, Balanced and Maximum actually change

High

Copies pages and keeps title, author, subject and keywords. It does not pack object streams. Use it when a workflow hashes documents or when a picky reviewer compares metadata. Savings are often modest. That is acceptable. It is the smallest behaviour change, not the smallest file.

Balanced

Clears those metadata fields, labels producer as Folio, and saves with object streams. Invoices, letters, slide decks and software manuals often lose leftover objects here. Text stays selectable if it was text. Images inside the file are not recompressed. This is the default for a digital export.

Maximum

The tightest save Folio offers with the same page-copy model. Title and author will not survive. Do not use it as a magic “make the scan 2 MB” button — it is not. If Balanced did nothing, Maximum usually will not invent a new codec either. It is not a third algorithm. It is a tighter save of the same copy.

Steps

1. Confirm you can select text
Open the PDF and try to highlight a sentence. If you cannot, leave this sequence. The scans guide is the honest next page. Looping High / Balanced / Maximum on a photograph of paper wastes time and does not change the pixels.
2. Open Compress and drop the file
Use the compress tab. You can add one PDF or several. Several successful outputs download as a ZIP. Each file still has to pass the 80 MB size guard on its own. That guard is RAM for the tab, not Gmail’s cap.
3. Start with Balanced
Read before and after sizes. If Balanced helps, download. If you need metadata to survive, use High instead and accept a smaller saving. If Balanced barely moved a digital export and title/author do not matter, try Maximum once — not in a loop.
4. Keep the tab open, then inspect the download
Work stays in memory. A phone may reload. If it does, try a laptop. Open the new file and try selecting a sentence. If you still need fillable fields, discard the compressed copy and keep the original form. Treat the output as a transmission copy, not a new print master.
5. Send it from your own tools
Folio does not email the result, does not give you a sharing link, and does not keep the job. Attach the file from Gmail, Files, or Finder yourself. Caps: email. Chat: WhatsApp. Close the tab when you are done.

Five reasons compress did nothing useful

The PDF is a scan: pictures of paper, not text objects. Folio does not downsample those pictures. The file is already linearized and lean: nothing to pack. The file is encrypted: we refuse it. The tab ran out of memory: you get a failure, not a half file. You needed OCR or PDF-to-JPEG: different products, and they usually want an upload.

A hybrid file — selectable captions plus full-page screenshots — will shrink only the wrapper. Split the screenshot pages if the remaining file is still over a cap. Compress does not drop pages. Split does.

Forms, text, and what the new file is

Selectable text in a digital PDF should remain selectable. Interactive forms, checkboxes and JavaScript often do not, because we do not rebuild the form catalog. Annotations that are already baked into page content usually still show. More on forms: FAQ. If a portal hashes the official file, send the master another way and use Folio only for a courtesy copy.

Versus Preview, Acrobat, and upload compressors

Preview and Acrobat can reduce file size with image downsampling when you export. They see the file because they run as apps you installed. Online compressors see the file because you uploaded it, and they often rasterize pages, which destroys selectable text. Folio sits in between: a tab, no upload, no rasterize, no miracle on scans. Pick the bargain that matches the document.

Packets after a shrink: merge only if you still need one file and each piece already fits. Real jobs (Gmail brochure, print shop vs mail copy) are on use cases. Operator: about Folio.

When High is the right first click

A reviewer who hashes documents, a court clerk who compares metadata, a workflow that still reads title and author — start on High. Savings are often modest. That is the point. Balanced and Maximum clear those fields and label producer as Folio. If the recipient’s script checks producer, they will notice. Say so in the email if you send a Balanced copy as a courtesy and the master another way.

High is not “the quality preset”. Folio does not recompress JPEGs on any of the three. People who pick Maximum because it sounds like “high compression” are reading a different product. Real packets: use cases. If the send is chat, stop treating this as mail — WhatsApp.

Frequently asked questions

Do my PDF files leave this device?+

No. Folio merge, split and compress run in this browser tab with JavaScript. The PDF bytes are read into memory on your phone or computer, rewritten there, and offered back as a download from that same tab. We do not provide an upload API for documents, we do not store PDFs on a server, and closing the tab discards the bytes. That is the difference from typical online PDF sites, which send the file to a machine you do not control.

Is Folio free? Is there a watermark or a daily cap?+

The three tools are free. Downloads are not stamped with a Folio logo, a URL or a ‘trial’ banner. We do not reset a counter at midnight. The practical limits are your device memory and the per-file size guard (currently 80 MB), not a paywall. The site is supported by advertisement placeholders that sit after a finished action and in the footer — never over the Merge, Split or Compress button.

What do High, Balanced and Maximum actually change?+

All three copy the pages into a new PDF. High keeps document title, author and keywords and does not pack objects into compressed streams. Balanced and Maximum clear those metadata fields, set producer to Folio, and save with object streams, which often trims files that were exported carelessly. None of the three recompresses photos inside a scan. Pick High when you want the smallest behaviour change; pick Balanced as the default; pick Maximum only if you do not care about title/author fields.

Do interactive forms still work after compress or merge?+

Not reliably. Folio copies page content into a new PDF. Fillable fields, checkboxes, dropdowns and JavaScript actions often belong to a form catalog that is not rebuilt. A form that you still need to type into should not be compressed or merged here — keep the original. A form that is already filled and flattened as marks on the page will usually still look filled, because those marks are page content, but it may no longer be editable.

Why does a scanned PDF barely get smaller?+

Most of a scan’s weight is the photograph of the paper, stored as images inside the PDF. Folio’s compressor rewrites the document structure: it can drop leftover metadata and pack objects more tightly. It does not downsample those photos, it does not run JPEG again, and it does not OCR the page into text. If the file is a 300 dpi colour scan, expect little or no saving. Born-digital PDFs (exports from Word, invoices, slides) shrink more often because they carry fonts, unused objects and fat metadata rather than photos of paper.

Does the text stay selectable after compress?+

Yes for text that was already real text, not a picture of text. Folio does not rasterize pages into a single image, so copy-paste and find-in-document still work on digital PDFs. A scan remains a scan: you cannot select words that were never encoded as text. If you need searchable scans, run OCR in a dedicated tool first, then use Folio only to merge or split the result.

How large can a PDF be, and can I process a batch?+

Each file is rejected above 80 MB before we try to parse it, because a larger PDF will often crash a tab. Merge accepts two or more PDFs in one go. Compress accepts one or more and zips the results if you add several. Split works on one PDF at a time so page numbers stay unambiguous. A ‘batch’ that is really twenty 40 MB scans will still be limited by RAM; if the tab struggles, do fewer files per pass.

When do ads appear, and do you ask me to click them?+

Ad slots are reserved after a successful download and in the footer, plus a mid-page slot below the how-it-works block. Until Google marks the site Ready they are placeholders, not live ads. We do not pay you to click, we do not instruct you to click, and we do not place ads over Merge / Split / Compress. Please do not click ads as a favour — that violates Google policy and can close the account.

Who runs Folio and how do I contact you?+

Folio is a local-first PDF utility maintained as a public tool, not a venture product with a sales team. For a bug, a broken PDF that should have worked, or a privacy question, email ultaultimatum@gmail.com. Include the page URL, the browser, and what you expected. Do not attach the PDF unless we ask — the whole point of this site is that documents stay with you. We do not offer phone support.

Gmail said my PDF is too large. What should I click?+

If you can select text in the PDF, open Compress and try Balanced, then Maximum. If you cannot select text, it is probably a scan — Compress will barely help. Split out the pages the recipient needs, or recapture the paper at a smaller size. Folio does not email the file and does not give you a Drive link. Details: the email size guide.

Will Folio shrink a scanned ID or a stack of photographed pages?+

Almost never in a way that matters. Those files are heavy because of the pictures inside, not because of PDF metadata. Folio does not downsample images and does not OCR. Split if you only need some pages. See the scans guide. Do not upload an ID to a random compressor.

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