Basics · Concept
What Is File Conversion?
Conversion sits between “I have this file” and “I need that format.” Sometimes it is a simple remux (same compressed data in a new container). Sometimes it is a full re-encode that changes quality and size.
Quick take: File conversion is rewriting a file from one format into another so a different app, device, or workflow can use it — ideally keeping the information you care about.
What conversion tries to preserve
Pixels, audio, text, layout, metadata — depending on the pair. Not everything can survive every conversion (transparency into JPG, editable Word structure into a flat PNG screenshot).
Conversion vs compression
Compression shrinks data inside a format (or with a similar one). Conversion changes the format identity. They often happen together — e.g. PNG → WebP — but they are different goals.
Private conversion
In Format Convertly, conversion runs in your browser: the file is read into local memory, transformed, and downloaded. Nothing is uploaded to a conversion server.
Key points
- Conversion changes format so another tool can open or ship the file.
- Some conversions remux; others re-encode and can change quality.
- Pick the target based on the destination’s constraints.
Examples
HEIC → JPG
Make iPhone photos open on Windows and most websites.
MKV → MP4
Move video into a container browsers and phones prefer.
CSV → JSON
Reshape tabular data for APIs.
Try it in a converter
Concepts stick better with a real file — processing stays in your browser.
Related concepts
FAQ
Does conversion always lose quality?
No. Lossless or remux paths can preserve quality. Lossy re-encodes can reduce it — choose settings carefully.
Browse all conversion concepts or jump to converters.