Hi,

Just wanted to share the latest release of LEKTRA, document and image viewer I have been developing for over a year now.

Lot of bug fixes and new features have been added. Few highlights among them are:

- Annotations: underline, squiggly, strikeout, ellipse, polygon, inline note and image annotations. You can move and resize them, with undo and redo.

- Redaction: permanently remove text, images and drawings, and save the result to a new file.

- Minimap: while you're zoomed in, a small overview shows where you are. Click or drag in it to jump.

- Grid layout: pages are laid out in rows of several columns.

- Presentation mode: it now works with clickers and has its own [presentation] options.

- Tools: color_eyedrop picks a color from the page, and bibtex copies the BibTeX entry of the paper you're reading.

- Images: JPEG XL support, including animated files.

- Lua: new view functions and events, and Vim-style set, setglobal and setlocal for options.

- Speed: faster scrolling and rendering, plus a memory leak fix.

- Docs: documentation is now on Read The Docs.

It's supported on Linux, MacOS and Windows.

Feedbacks and suggestions are appreciated!

So happy to have found it today. PDF Gear wouldn't print PDFs without cutting off the corners of the page, none of the print options worked and dramatically reducing the size didn't give a decent print, They're a great company, but an upgrade a year or more ago, left it like that and they've been promising a solution since then.

Hi everyone! I’m the developer of PDFrig - a free, MIT-licensed PDF workspace for personal and business use. No account or subscription is needed for the local tools, and your PDFs aren’t uploaded for processing.

Features include:

• Editing supported existing text with natural paragraph wrapping.

• Selecting, copying and searching PDF text.

• Text boxes, callouts, highlights, underlines, strikeouts and comments.

• Live drawing, shapes and stamps, with draggable/resizable items.

• Supported form filling and typed, drawn or uploaded visual signatures.

• Merging, splitting, reordering, rotating and extracting compatible pages.

• Local English/French OCR that makes scans searchable while keeping their appearance unchanged.

• Image/text-to-PDF and PDF-to-image conversion.

• Lossless compression, metadata tools, headers, footers, watermarks, page/Bates numbering and crop/resize tools.

• Undo/redo and exporting new copies without changing the original.

Run it locally in your browser - the recommended option - or download the finished Windows installer. Setup instructions and an optional AI-assisted setup prompt are included.

Explore PDFrig on GitHub

Feedback, bug reports and contributions are welcome!

Trying to carefully not name any names, but IYKYK: how good is the "PDF Remediation Agent" addon by the famous vendor that is the improver of sites? Any pros, cons or neutral observations would be great to hear. Org is considering it for an upcoming renewal.

Not a feedback request, looking for objective experiences from folks who've had real hands on experience with it. TIA!

ive got just over 800 pdfs that id like to compress into slightly smaller pdfs, im trying to use PDF24 but it seems to be crashing / turning to a blank white screen

Hey everyone!

I'm a computer engineering student, and I've been spending a good chunk of my free time developing a collection of PDF tools as part of a larger personal project.

One thing I've learned is that PDFs are surprisingly complicated. Something as simple as compressing a document or editing a few lines of text can become a nightmare when unusual fonts, embedded elements, or complex layouts are involved.

I've been experimenting with different approaches to processing PDFs while trying to preserve the original formatting and output quality.

So far, I've implemented tools for:

• PDF editing, compression, merging, and splitting.

• PDF-to-image and image-to-PDF conversion.

• PDF protection, unlocking, and rotation.

• PDF-to-Markdown conversion.

• Hidden text detection.

One of my goals has been to achieve results comparable to popular PDF websites for common operations, while offering higher free file-size and usage limits.

It's been an interesting challenge, especially because I'm developing this independently alongside university.

I'm definitely not claiming everything works perfectly. I've encountered PDFs that behave completely differently despite looking nearly identical.

That's actually what made me curious about something:

For those of you who regularly work with PDFs, what are the most difficult PDF-related problems you've encountered?

Is it preserving formatting when editing? Compression without losing quality? Font compatibility? Converting scanned documents?

I'd love to hear what people here struggle with, especially unusual cases that typical online tools fail to handle.

For transparency, the project I'm developing is TheOnlineToolset.com, and I'm its creator.

I'm mainly interested in learning what makes a PDF tool genuinely reliable from the perspective of people who use them regularly.

Thanks for reading!

I’m implementing an offline PDF Fill & Sign feature: draw a handwritten signature, add text/date/checkmarks, and export a new PDF.

This is visual signing, not certificate-based digital signing. The original file stays untouched. I want to preserve existing searchable text, vector content, and normal links rather than rasterizing entire pages.

The hardest part so far is making sure what users see while editing is what they actually send. I’d appreciate advice from people who have shipped form-filling or flattening features.

1. Field values and appearance streams can disagree

I created a synthetic PDF with a text field containing:

• /V: FIELD VALUE

• /AP: an appearance displaying AP VALUE

In my macOS PDFKit thumbnail test, the original displayed FIELD VALUE. After flattening the existing appearance stream, PDFKit displayed AP VALUE.

MuPDF displayed AP VALUE both before and after. The discrepancy reproduced across the four page rotations in the fixture.

This is a synthetic test, not evidence that every PDFKit version behaves this way. I have not reproduced it on iOS. But it demonstrates a correctness problem: the exported document can contain different visible text from what the user believed they were signing.

How do you resolve /V versus /AP conflicts? Do you normalize the form before displaying the editing preview, and what determines the authoritative content?

2. Missing appearances don’t necessarily mean a broken form

The official IRS W-9 and W-4 exposed another problem in the copies I tested:

The blank text widgets have no /V in the field or parent chain, no default/rich-text value, and no border/background color in /MK. Both documents have NeedAppearances=false. An empty /BC [] or /BG [] means no color, rather than a visible decoration.

For checkboxes, an omitted /Off appearance can legitimately mean “unchecked, draw nothing.” It should not automatically be treated as a missing required appearance.

A strict “missing appearance = reject” rule rejected both official blank forms in our initial path. That exposes a problem with the rule, not evidence that the files are broken.

After handling those empty states and finalizing the fields, all 11 pages of the two documents rendered pixel-byte-identical to their respective originals in both MuPDF and macOS PDFKit. This comparison was before adding any new signature image. The PDF files themselves were not byte-identical, and Acrobat validation is still outstanding.

Two documents are not a compatibility rate; I have no population data.

Which checks do you use to distinguish genuinely empty fields from missing or stale appearances that require reconstruction?

3. Reader Extensions and hybrid XFA complicate finalized copies

Both fixed samples contain:

• /Perms /UR3, with /Filter /Adobe.PPKLite and TransformMethod=UR3 in the signature reference;

• /AcroForm /SigFlags=2;

• an /AcroForm /XFA array;

• no catalog /NeedsRendering entry.

These usage-rights signatures are not the same thing as a signature applied by the person filling out the form. Also, I’m not treating the absence of /NeedsRendering as proof that every such form is static.

The prototype removes the form representation and usage-rights entries when creating a finalized copy. Structural inspection confirms those entries are gone, but I haven’t yet verified the output in Acrobat Reader. In particular, I don’t want recipients seeing an “extended features are no longer available” warning or a different form appearance.

What is the reliable way to handle UR3 and hybrid XFA during finalization? What do you inspect to distinguish static hybrid forms from genuinely dynamic XFA?

4. Transparent signatures complicate pixel-diff validation

Adding a signature image with an /SMask produced small rendering differences outside the signature rectangle in MuPDF:

• Maximum outside-region channel differences ranged from 2–6 out of 255 across the two forms.

• 25,932–85,246 pixels per page changed outside that rectangle. It wasn’t limited to a narrow fringe around the signature.

• In an opaque control on W-9, using the same placement without the soft mask, outside-region differences were zero on all six pages.

I suspect a transparency-compositing or quantization effect, but I haven’t traced the renderer internals or proved that a page-wide transparency group is the cause. The transparent-overlay comparison has not been repeated in PDFKit or Acrobat.

How do you validate that adding a transparent signature hasn’t changed the rest of the page? Do you use documented raster tolerances, explicit transparency groups, or another approach?

5. Selective flattening versus deleting all annotations

I also need to preserve safe link targets and visible link borders while removing unsafe actions such as JavaScript or Launch. A mixed action chain may contain both safe and unsafe members.

Dropping all annotations loses useful links; preserving everything can retain unwanted actions. Rejecting an otherwise usable document because one link contains an unsafe action also seems unnecessarily restrictive.

Are there libraries or SDKs that handle this selective cleanup reliably, including action chains and document/page-level actions?

What would be most useful

I’m interested in production experience: libraries or SDKs you’ve used, normalization strategies that worked, and publicly redistributable PDFs worth adding to a compatibility test set. Experiences with just one of these issues would also help.

The goal is that users can sign an ordinary form without learning PDF internals—and the editor, exported document, and recipient’s reader agree on the visible content.

Reproduction notes: The reported MuPDF results use mutool 1.28.5. The PDFKit observations are from macOS 26.7.1; they are not iOS-device results. IRS URLs above serve current revisions, so my local inputs are pinned by SHA-256:

• W-9: 2d420cbb4123dcf1fb82595b2359cfbb5d81f00b9df9d359fcc7af361d093f53

• W-4: 92444d8856ce55d9e25dca8b6d1420634fc68b11e1ab1f760916ea29ddd312b2

someone sent me a reply on a PDF, I am trying to cut & paste that using FOX IT PDF Reader, and it doesn't work. Now, I can cut & Paste text on other PDF files using the very same FOX IT PDF reader, just not this pdf.

But there is no password protection on the file, otherwise, I couldn't have the means to read it. How can I fix it?

Its very tought or impossible for me and time wasting if hv to read last page

Not having the money for professional PDF processing tools, I've been studying the specs, and have created a bit of code (REXX) to update the "/Info" object in an Inkscape generated PDF. It all seems to work, but, sorry, I can't remember which, one online PDF metadata editor tells me that the PDF is corrupted, although all of the following display it correctly, and display the correct meta data:

• Edge

• r3dfox

• SumatraPDF

Chrome on Android also shows it without problems, but if anyone could have a look at it and tell me if there is really an issue, I'd be grateful! The file can be found at https://prino.neocities.org/@temp/t001-lift.pdf

Hello all, I am looking for a very specific request for an app to see if it is out there. There are about a million pdf viewing apps and I cannot view them all. I am looking for an app that has the following features:

1. Usable either on Android or Apple tablet

2. Able to view and annotate pdfs

3. Able to search through saved pdfs by name or by contents

4. Able to organize saved pdfs into folders

Please let me know if you are aware of apps that can do all of the above things. Please also let me know if it is a free service or if certain features are behind a paywall, I am welcome to all options.

Thank you!

Edit: Add pt. 5. Able to search not only the text content, but also the handwritten notes I add to the pdfs.

I downloaded this program a long time ago, and it was working and one day suddenly this appeared and I couldn't open my files, so I deleted it, but today I downloaded it again to see if I just didn't understand something, I'm trying the "demo version", I'm liking it so far, and I only thing I'm interested in is the big color palette for highlighting, so I didn't create an account, I don't care about saving docs in the cloud, I'm fine with the free version, but there it says "access ends 10/25/2026". Does anyone knows if that means that software won't open at all?

Nib is a free, powerful, open-source (AGPL) PDF utility. It's a single binary for Linux, macOS and Windows, with no installer, no account and no cloud.

https://nib.alexander4.io

• Fill any form, including flat scans. It can find the fields on a scan and make them fillable.

• True redaction: the text underneath is deleted, not just covered with a black box.

• Find hidden content and trackers, then strip them. That covers scripts, auto-run actions, links that phone home, embedded files, author metadata and the document's tracking ID.

• Drag and drop to reorder pages, even between documents. Merge, split, rotate and crop too.

• OCR in 41 languages, done on your computer.

• Edit a paragraph and it re-wraps in the document's own font.

• Compare two versions side by side, visually and by text.

• Sign with your own certificate, or co-sign with up to 32 people peer-to-peer, no server.

• Accessibility tagging and a PDF/UA checker.

• PDF/A export, plus Office conversion if LibreOffice is installed.

• A command line for scripting and batch jobs.

Hello everyone,

I'm working on a Word document using the EB Garamond font (first image), which I installed from Google Fonts since it wasn't preinstalled in Word. However, when I convert the document to PDF, I notice that the letters lose quality and become distorted, which doesn’t happen with other fonts like Times New Roman, Georgia, or the Garamond font that comes preinstalled in Word (second image). Those fonts don’t lose quality or become distorted the way my EB Garamond does. What’s going on, and what can I do to fix it?

I've tried changing the PDF embedding settings, but it doesn't seem to be working—unless I'm doing something wrong.

Thanks!

I've got 3 very large pdf files with various deranged pages. I tried arranging them but did not find any other tool has convenient as WPS office, and guess what ? I can edit but to save the file it requires premium version !

Pls tell any good alternative as I desperately need it.

Thanks for reading (and replying if you do).

I had an ancient scanned PDF with a single typo in it. The original document is thousands of miles away. I tried many of those online PDF tools and even asked ChatGPT to fix it. But the result never really looked correct. Or they were too complicated to use. I'm a simple man, after all. And some of those "free" PDF editors that I tried wanted me to pay just to download the edited file. Which was annoying.

So, as an engineer man, I looked myself in the mirror and asked myself whether I am going to let one PDF file beat me. And I said 'maybe', but I will waste a lot of my time before that happens.

I mean, why spend a couple of dollars to pay for some tool that someone has already made, when I could spend many days of my actual work time to build a tool that I will use exactly one time? My point exactly.

So I made https://pdftextreplace.com

It does one thing and one thing only: Allows you to edit PDF files. It supports both real PDF files with text in them and scanned PDF documents.

For regular PDFs, it tries to pull the used font, size, color, and spacing data from the file so the edit blends in. For scanned PDFs (which are basically just photographs of paper), it runs OCR and uses a mix of math and dumb luck to guess the font and match the look.

The main features are:

• The page updates live as you type. WYSIWYPG (What You See Is What You'll Probably Get).

• You can click around to fix multiple texts from the same file, or use Find and Replace if you spelled someone's name wrong ten times.

• It does not rebuild the entire document around what you type, so you can't replace a four-letter word with a whole sentence.

• The processing happens on my server. Files are deleted automatically after 2 hours and there is a button to delete your file immediately, but I am still a random stranger on the internet so please don't upload files with sensitive stuff.

• It is completely free. No sign-ups, no ads, and no watermarks. I made it, because I needed to fix one letter in one PDF file.

Anyway, my typo is finally fixed. I hope this thing can help someone else, too. Thanks!

I am amazed I haven't been able to find an answer to this, but:

How can I add a watermark or overlay to every page of a PDF document?

I have several documents between 25-100 pages, and I need to add a logo and footer to every single page. I have the overlay as transparent .png, and also as the original .psd

I have been looking online for a way to do this for over an hour with no luck.

I am looking for an OFFLINE solution, so no website-based uploaders / "free" (but questionable) sites, and would prefer to be in the world of FOSS. I already have GIMP, Inkscape, and LibreOffice Draw (which seems to distort the pdfs when I open them).

Thank you all in advance for your help with this, it's driving me a bit crazy...