Lock PDF - unlimited size Gratis

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Up to 100 MB for PDF and up to 25 MB for DOC, DOCX, RTF, PPT, PPTX, JPEG, PNG, JFIF, XLS, XLSX or TXT
Note: Integration described on this webpage may temporarily not be available.
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Discover the simplicity of processing PDFs online

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Upload your document in seconds
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Fill out, edit, or eSign your PDF hassle-free
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Download, export, or share your edited file instantly
Top-rated PDF software recognized for its ease of use, powerful features, and impeccable support
Users Most Likely To Recommend - Summer 2025
Grid Leader in Small-Business - Summer 2025
High Performer - Summer 2025
Regional Leader - Summer 2025
Easiest To Do Business With - Summer 2025
Best Meets Requirements- Summer 2025

Every PDF tool you need to get documents
done paper-free

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Create & edit PDFs

Generate new PDFs from scratch or transform existing documents into reusable templates. Type anywhere on a PDF, rewrite original PDF content, insert images or graphics, redact sensitive details, and highlight important information using an intuitive online editor.
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Fill out & sign PDF forms

Say goodbye to error-prone manual hassles. Complete any PDF document electronically – even while on the go. Pre-fill multiple PDFs simultaneously or extract responses from completed forms with ease.
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Organize & convert PDFs

Add, remove, or rearrange pages inside your PDFs in seconds. Create new documents by merging or splitting PDFs. Instantly convert edited files to various formats when you download or export them.
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Collect data and approvals

Transform static documents into interactive fillable forms by dragging and dropping various types of fillable fields on your PDFs. Publish these forms on websites or share them via a direct link to capture data, collect signatures, and request payments.
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Export documents with ease

Share, email, print, fax, or download edited documents in just a few clicks. Quickly export and import documents from popular cloud storage services like Google Drive, Box, and Dropbox.
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Store documents safely

Store an unlimited number of documents and templates securely in the cloud and access them from any location or device. Add an extra level of protection to documents by locking them with a password, placing them in encrypted folders, or requesting user authentication.

Customer trust by the numbers

64M+
users worldwide
4.6/5
average user rating
4M
PDFs edited per month
9 min
average to create and edit a PDF
Join 64+ million people using paperless workflows to drive productivity and cut costs

Why choose our PDF solution?

Cloud-native PDF editor

Access powerful PDF tools, as well as your documents and templates, from anywhere. No installation needed.

Top-rated for ease of use

Create, edit, and fill out PDF documents faster with an intuitive UI that only takes minutes to master.

Industry-leading customer service

Enjoy peace of mind with an award-winning customer support team always within reach.

What our customers say about pdfFiller

See for yourself by reading reviews on the most popular resources:
it was immediately available. it seems fairly straight ahead, but I've not had time to really check it out. each time I use it , it gives me a litle anxiety
Debbie C
2017-04-12
Excellent experience! It's fantastic. Ir brought me the beso solution to correct mistakes in pdf documents. Really useful tool!! I will recommend ir to my friends.
Alcira S
2017-05-04
I have used other PDF form fillers, but this is definitely nicer and easier to use. I am jumping through the VA hoops to try to get a pension for my brother. PDF filler just made it so much easier. I downloaded all of the forms that needed filled and had them all done in no time. I really like this app.
Cheryl A
2017-07-27
Easy to use. Lots of Features. Need to pay a few more dollars to use everything, but great value if you need to combine different documents to create one.
Andrew M
2018-10-26
What do you like best?
The Best Part is the Ease of Use and very intuitive.. The ease of editing any PDF files and so easy to send my real estate contracts to be signed from anywhere!!! And it is Priced just right!!!
What do you dislike?
Hummm.... I really can not think of any! At first it was hard to navigate, but once you know where everything is .. its very easy.. I really don't know why anyone would use DocuSign, the y charge so much for so little.
Recommendations to others considering the product:
I would give it a try.. I did and love it.. so easy to use.. and so affordable.
What problems are you solving with the product? What benefits have you realized?
I mainly use Pdf Filler for having real estate contracts signed by my sellers & buyers.. but its great for editing any pdf file..
Rizalito Guevarra
2019-05-21
What do you like best?
The program is user friendly and helps me with the essential tools I need to fill in and change my PDF files. I use this on a daily basis for work and works very well with other programs I use.
What do you dislike?
The font match is the only downside of the program i face especial when I have to fill in words and characters onto the document. It takes time for to match the font that is similar to the original font. Collating pages in a certain order is difficult for me but I decided not to use this feature.
What problems are you solving with the product? What benefits have you realized?
I am facing no problems using the program. The main benefit I use this program is the editing of the documents revived for out business to use for our needs.
User in Transportation/Trucking/Railroad
2019-05-28
Form-Filler Heaven 1. You have the forms I need; 2. the platform is user friendly, in general; 3. completion of forms is easy to navigate, specifically; 4. the ability to save in multiple formats; 5. the ease and ability to send completed forms is great; 6. The absolutely essential ability to easily sign documents in script via the 'sign' feature; 7. Overall, a useful, convenient app, that's nicely done. Thanks.
Dr. ABH
2023-03-02
This review is based on experience with the program itself I loved it. It was simple to use and I loved that I could save my documents and go back in and edit them again whenever I wanted. The only thing I didn't really like was the price. I opted to go with the monthly subscription because I knew I didn't need the program for a long period of time. I have used other programs on a monthly service before and have paid cheaper. However, still loved the overall use of the program, and I was able to cancel my subscription without an issue as well.
Valerie
2020-09-14
Feature filled and easy to use. I've had an overall great experience using PDFiller. The variety of features gives me the convenience to edit my documents, save them, upload them to my account and allows me to easily send them by email to be signed.
Daniel Gonzalez
2020-06-11

Lock PDF - Unlimited Size Feature

Lock PDF offers a unique solution for securing your documents of any size. With our unlimited size feature, you can lock large files without compromising their integrity. Protect your important information effortlessly.

Key Features

Unlimited file size for locking documents
User-friendly interface for quick setup
Strong encryption to keep your documents safe
Multiple formats supported for versatility
Easy sharing options after locking

Potential Use Cases and Benefits

Secure sensitive business contracts
Protect personal documents like tax returns
Share confidential information without fear of exposure
Lock academic papers before submission to prevent tampering
Maintain document privacy for legal agreements

By using Lock PDF, you will solve the problem of document security. Our tool allows you to lock files of any size, ensuring that your information remains confidential. Make your document protection process simple and effective with Lock PDF.

Get documents done
from anywhere

Create, edit, and share PDFs even on the go. The pdfFiller app equips you with every tool you need to manage documents on your mobile device. Try it now on iOS or Android!

For pdfFiller’s FAQs

Below is a list of the most common customer questions. If you can’t find an answer to your question, please don’t hesitate to reach out to us.
What if I have more questions?
Contact Support
Open the PDF file you need to shrink and choose File > Export. In the File window, make sure the Format is PDF, then choose To reduce File Size from the Quartz Filter drop-down. The resulting PDF will be much smaller, but the quality will be somewhat compromised (although acceptable for viewing and even draft printing).

#1 usability according to G2

Try the PDF solution that respects your time.
Users Most Likely To Recommend - Summer 2025
Grid Leader in Small-Business - Summer 2025
High Performer - Summer 2025
Regional Leader - Summer 2025
Easiest To Do Business With - Summer 2025
Best Meets Requirements- Summer 2025