Free Online Converters
File Converters
Free, browser-based file converters that work without uploading to a server. Your files stay on your device — private, instant, and no sign-up required.
Available now
Click to open the converter instantly — no upload to a server, no account needed.
Convert iPhone and Apple device photos from HEIC or HEIF format to a universally compatible PDF — entirely in your browser. No file is ever uploaded to a server, making this the most private HEIC to PDF converter available. Drag and drop one or multiple HEIC images, adjust page size if needed, and download the resulting PDF instantly. Works on Windows, Mac, Android, and iOS.
Open converterFiles never leave your device
All conversions run locally in your browser. Nothing is sent to PreciseCalcs or any cloud server.
Instant results
No waiting for server processing or download queues. Conversions happen at local processor speed.
Works on any device
Mobile, tablet, or desktop — no app installation required. Open in any modern browser and convert.
No file size limits
Because conversions run locally, there are no server-side size restrictions or per-file quotas.
Coming soon
More popular file converters are being built — all following the same browser-only, no-upload approach.
Combine one or multiple JPG or PNG images into a single PDF document. Control page orientation and margins — all in the browser.
Extract every page of a PDF as a high-resolution JPG or PNG image. Choose individual pages or export all at once as a zip file.
Convert images to Google’s WebP format for 25–35% smaller file sizes with no visible quality loss. Ideal for web performance optimisation.
Rasterise SVG vector files to PNG at any resolution — 1×, 2×, or custom pixel dimensions. Perfect for exporting icons and logos for web and print.
Resize any JPG, PNG, or WebP image to exact pixel dimensions or by percentage. Maintains aspect ratio by default. Runs locally — no upload needed.
Compress JPG and PNG files for web use with adjustable quality settings. Reduce file sizes by up to 80% with minimal visible quality loss — browser only.
Who uses these file converters?
Anyone who needs to convert, resize, or compress files without sending them to an unknown server.
iPhone Users
Convert HEIC photos to PDF or JPG so they can be shared, printed, or submitted on any platform.
Web Developers
Export SVGs to PNG, convert images to WebP, and compress assets to hit Core Web Vitals targets.
Students & Writers
Combine images into a PDF for submission, or compress screenshots for email and document attachments.
Professionals
Convert photos to PDF for invoices, ID documents, and client deliverables that need universal compatibility.
Privacy-Conscious Users
Convert sensitive documents and photos without uploading them to a third-party cloud service.
Frequently asked questions
Are my files actually private? Do they get uploaded anywhere?
No files are ever uploaded to PreciseCalcs or any external server. All conversions run entirely in your browser using JavaScript and the browser’s built-in file APIs. Your files stay on your device throughout the entire process. This is the fundamental difference between our tools and most online converters, which upload your files to a cloud server for processing.
What is HEIC and why do iPhone photos use it?
HEIC stands for High Efficiency Image Container (also called HEIF — High Efficiency Image Format). Apple adopted it as the default photo format from iOS 11 onwards because it produces images that are roughly half the file size of JPEG at the same visual quality. The downside is that HEIC is not natively supported by Windows, most Android devices, or many web platforms — which is why converting to PDF or JPG is so often needed.
Will image quality be lost when converting?
For HEIC to PDF conversion, the image is embedded at full resolution so quality is preserved. For future JPG and WebP converters, quality will be adjustable — you’ll be able to choose between maximum quality (larger file) and compressed quality (smaller file). PNG to PNG conversion is always lossless. SVG to PNG is rasterised at the resolution you specify.
Are there any file size limits?
Because conversions run locally in your browser, there are no server-imposed size limits. The only practical constraint is your device’s available RAM — very large files (over 200 MB) may be slow or may cause your browser to use significant memory. For most typical images and documents this is not an issue.
What file formats will be supported in future?
The planned roadmap includes JPG/PNG to PDF, PDF to JPG, PNG/JPG to WebP, SVG to PNG, an image resizer, and an image compressor. All will follow the same browser-only approach — no uploads, no accounts. Visit the blog or check back on this page for release announcements.
Need a different type of tool?
PreciseCalcs also covers construction, time & date, food & kitchen, science & lab, math, and developer tools — all free, no sign-up required.