OpenOne PDF Converter & Viewer

Open files. Convert PDFs. Keep your documents together.

OpenOne combines a PDF converter, PDF reader, and file viewer for Android. Turn photos into PDF documents, export PDF pages as images, and preview Word, Excel, PowerPoint, and HWP files in one app. Use it for work documents, class notes, receipts, and everyday paperwork.

CONVERT PHOTOS AND IMAGES TO PDF
• Convert JPG, PNG, and other supported images into a PDF.
• Combine multiple pictures into one multi-page document.
• Arrange images in the order you need.
• Capture a paper document with your camera and save it as a PDF.
• Open and share your finished PDF.

CONVERT PDF TO JPG OR PNG
• Save PDF pages as JPG or PNG images.
• Export all pages or choose a specific page range.
• Select the output resolution for your task.
• Share selected pages as images through messaging or email apps.

MERGE PDF FILES AND ORGANIZE PAGES
• Combine multiple PDFs in your preferred order.
• Extract selected pages into a new PDF.
• Reorder, rotate, or remove pages.
• Save the result as a separate file while keeping the original PDF.

READ PDF AND PREVIEW OFFICE DOCUMENTS
• Zoom into PDFs, jump to a page, and resume reading.
• Preview text from Word DOC and DOCX files.
• Browse Excel XLSX worksheets and cells in a table.
• Preview slide text from PowerPoint PPT and PPTX files.
• View paragraphs and tables from Korean HWP and HWPX documents.
• Read TXT, CSV, Markdown, and other text or data files.
• Preview EPUB book content and inspect file lists inside ZIP archives.

MANAGE IMAGES AND FILES
• Zoom into photos and images.
• Resize multiple images and compress JPG or PNG files.
• Rename files in batches with naming rules.
• Find documents with recent files, filename search, type filters, and favorites.
• Open files received from other apps and share them when needed.

DOCUMENT PROCESSING ON YOUR DEVICE
File viewing and conversion happen on your device without uploading documents to a server. No account or sign-in is required to open documents. Dark mode and layouts for phones, foldables, and tablets help you read comfortably.

AVAILABILITY
Preview support varies by file format. Some HWP and Office documents display extracted text or tables, and may differ from the original formatting or layout. The free version includes ads and item limits for batch tasks. A one-time PRO purchase removes ads and unlocks those batch limits.

Recent changes:
• Improved PDF merging, page organization, and image export screens.
• Updated batch settings and the PRO purchase and restore screens.
• Added ads to the free version. PRO removes all ads.
• Improved layouts for large text, tablets, and landscape mode.