Software Alternatives, Accelerators & Startups

Fast-Convert.net VS KeptPDF

Compare Fast-Convert.net VS KeptPDF and see what are their differences

Fast-Convert.net logo Fast-Convert.net

Convert between 140+ unit categories instantly. BMI, calorie, loan calculators. PDF merge, split, compress tools. All free, fast, and accurate.

KeptPDF logo KeptPDF

Redact, edit, OCR, and sign PDFs entirely in your browser. The file never leaves your device. Free, no account needed.
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  • Fast-Convert.net
    Image date //
    2026-05-10
  • Fast-Convert.net
    Image date //
    2026-05-10

Free online unit converter and PDF tools. Convert length, weight, temperature, area, speed, and more. Merge, split, compress, and convert PDF files instantly. No sign-up required. Available in Arabic and English

  • KeptPDF Landing page
    Landing page //
    2026-08-22

KeptPDF is a PDF toolkit that runs entirely in your browser. Nothing uploads: every tool runs on your own device, so the document never touches a server.

What it does:

  • Redaction that auto-detects names, SSNs, phone numbers, addresses, and dates, then removes the underlying text instead of drawing a box over it. Every redacted file gets an audit certificate that anyone can verify.
  • OCR that makes scanned PDFs searchable, with on-device processing.
  • Sign, annotate, compare, organize, split, merge, compress, convert, watermark, Bates numbering, exhibit stamps, and more. About 25 tools in total.
  • A command line version runs the same redaction engine on your own servers for bulk work: scanning bureaus, litigation support teams, and records departments process thousands of PDFs in one pass.

Who it is for: law firms, accounting practices, clinics, and anyone who shares documents they cannot afford to leak.

The core tools are free with no sign-up. Works offline as an installable app.

Fast-Convert.net features and specs

  • Free to Use
    Fast-Convert.net offers free file conversion services, allowing users to convert files without paying for software or subscriptions.
  • No Software Installation Required
    As a web-based tool, users can convert files directly in their browser without needing to download or install any software on their computer.
  • Multiple Format Support
    The platform supports a variety of file formats for conversion, including documents, images, audio, and video files, making it a versatile tool for different needs.
  • Simple Interface
    The website features a straightforward and easy-to-navigate interface, allowing users to quickly upload files and convert them without a steep learning curve.
  • Fast Conversion Speed
    As the name suggests, the platform aims to provide quick file conversions, saving users time compared to some other online converters.

KeptPDF features and specs

  • Simple PDF Editing
    KeptPDF offers straightforward tools for editing, merging, splitting, and converting PDF files, making it accessible for users who need quick document management without a steep learning curve.
  • Web-Based Accessibility
    Being a web-based tool, KeptPDF can be accessed from any device with an internet connection, eliminating the need for software installation and allowing use across different operating systems.
  • Multiple File Format Support
    The platform supports conversion between PDF and various other file formats, offering flexibility for users who work with documents in different formats.
  • No Installation Required
    Since it operates in a browser, users can save storage space on their devices and avoid compatibility issues that sometimes arise with desktop software installations.
  • Quick Processing
    KeptPDF is designed to process PDF tasks efficiently, allowing users to complete common document tasks like compression or conversion in a relatively short amount of time.

Analysis of Fast-Convert.net

Overall verdict

  • Fast-Convert.net appears to be a straightforward online file conversion tool that offers quick, browser-based conversions without requiring software installation, making it a convenient option for casual users. However, as with any online converter, users should verify its security practices and privacy policy before uploading sensitive files, and reviews of its reliability may be limited.

Why this product is good

  • No software installation required, as conversions happen directly in your web browser
  • Fast and simple interface designed for quick file conversions
  • Free to use for basic conversion needs
  • Accessible from any device with an internet connection
  • Supports common file formats for everyday conversion tasks

Recommended for

  • Casual users who need occasional, quick file conversions
  • People who prefer web-based tools over installing desktop software
  • Users working with non-sensitive documents or media files
  • Those looking for a free solution for simple format conversions
  • Anyone needing to convert files on the go from multiple devices

Fast-Convert.net videos

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KeptPDF videos

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Category Popularity

0-100% (relative to Fast-Convert.net and KeptPDF)
Unit Converters
100 100%
0% 0
PDF Readers And Editors
0 0%
100% 100
Online Converters
100 100%
0% 0
PDF Tools
50 50%
50% 50

Questions & Answers

As answered by people managing Fast-Convert.net and KeptPDF.

What makes your product unique?

KeptPDF's answer:

KeptPDF runs entirely in your browser. Your file, and the text inside it, never leaves your device. Not to an AI, not even to us. You can open your browser's network tab and watch: the document bytes never go out.

Most online PDF tools upload your file to a server first, and some "AI redaction" services quietly send your document text to a third-party model. That is the exact risk people are trying to avoid when they redact something.

KeptPDF also does true redaction. The text is removed from the file, not covered with a black box you can copy out later. Every redaction produces a verification certificate you can share with the file.

Why should a person choose your product over its competitors?

KeptPDF's answer:

Three reasons.

Privacy you can verify, not just a promise. Processing happens locally in the browser, so there is no upload step to trust. We do send anonymous usage counts for quota, and we say so plainly, but never your document.

Real redaction with proof. Removed text is permanently gone, and you get a certificate showing the file was checked for leftover extractable text. Automated detection cannot catch everything, so a final human review is still your job, and the tool says that too.

It works on a phone. Most PDF suites assume a desktop. KeptPDF was built and used on a phone first, so redacting a document while you are standing in a hallway actually works.

How would you describe the primary audience of your product?

KeptPDF's answer:

Anyone who has to hand a document to someone else and needs the sensitive parts gone first.

In practice that is solo attorneys and small law firms, accountants and tax preparers, healthcare and records staff handling requests, HR teams, and individuals dealing with their own medical, legal, or financial paperwork.

The common thread is not an industry. It is a person who cannot upload a confidential file to a random website, and who does not have an enterprise IT budget to solve it.

What's the story behind your product?

KeptPDF's answer:

A family member got seriously ill. We spent most days at the hospital, and straight answers were hard to come by, so we leaned on AI tools to make sense of the records, notes, and lab results.

But you cannot paste a medical record into an AI chat. You have to strip the names, the ID numbers, the diagnoses first. And almost every tool we found either wanted to upload the whole file to a server, or "auto-redacted" by sending the document text to an online AI. That was the exact thing we were trying to avoid.

Most of this was happening on a phone, at a bedside. So I built the tool I needed: redaction that runs on the device, works on mobile, and never sends the file anywhere. That turned into KeptPDF, which is now a full PDF suite with over 20 tools, all local-first.

Which are the primary technologies used for building your product?

KeptPDF's answer:

The app is plain JavaScript with no front-end framework, which keeps it fast and keeps the code auditable.

PDF work happens in the browser using pdf.js for rendering and pdf-lib for writing. Text recognition uses Tesseract running as WebAssembly. Password and encryption handling uses a WebAssembly build of qpdf. It is a Progressive Web App, so it installs and works offline.

The thin server side is Node on Vercel, with Postgres for accounts, Stripe for billing, and Resend for email. None of those ever see a document.

Who are some of the biggest customers of your product?

KeptPDF's answer:

KeptPDF is early and independent, and we do not publish customer names. The product is privacy-first by design: we never see your documents, and we do not track who our users are or what they work on. Publishing a client list would sit badly next to that.

The user base today is mostly solo attorneys, small firms, accountants, and individuals handling their own records.

User comments

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What are some alternatives?

When comparing Fast-Convert.net and KeptPDF, you can also consider the following products

iLovePDF - Premium online PDF tool set

Smallpdf - PDF document management and conversion suite

Every Unit Converter - Free unit converter for metric to standard, imperial, and all measurement units. Convert length, weight, temperature, pressure, energy, torque, and more. 47 converters. Instant results. No signup.

Sejda - Split, merge and other powerful PDF tools.

Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.

Convert - This online unit conversion tool will help you convert measurement units anytime and solve homework problems quickly using metric conversion tables, SI units, and more.