A File Converter That Does Not Upload Your Files
Changing a file from one format into another should take a minute. Searching for an existing tool often makes that ordinary task feel suspiciously expensive instead.
Some sites ask for the file before explaining what happens to it. Some put the real download button between ads that look almost identical. Others work, but look as if nobody has revisited the interface in fifteen years. Completing one conversion is easy; the harder question is why such a routine operation should require handing a file to an unfamiliar service.
The useful version of “online”
I wanted the convenience of a website without turning the file into a server-side job. LocalConvert downloads the conversion engine, then runs it inside the browser using the computer already in front of you.
Images use the browser's Canvas APIs. They can be resized, center-cropped, rotated, and compressed before export. Multiple images can become a single PDF, while existing PDFs can be merged, reordered, reduced to selected pages, or rotated with pdf-lib. Video and audio use a WebAssembly build of FFmpeg to produce MP3, WAV, or M4A, with optional trimming and bitrate controls. Vercel serves the interface and the conversion code, but it never receives the selected file. There is no upload route to call.
That distinction matters more than a privacy badge. “We delete uploads later” still begins with an upload. Here, the file stays in the tab from selection through download.
Fewer choices, but real ones
Universal converter websites often advertise an enormous format count. The number is impressive until the interface offers combinations that are meaningless, unreliable, or impossible in the browser.
This tool starts smaller and treats support as a tested matrix:
- MP4, MOV, MKV, AVI, WebM, M4A, WAV, FLAC, OGG, AAC, or MP3 to MP3, WAV, or M4A
- optional audio trimming and 96/160/256 kbps output profiles
- PNG, JPG, WebP, and BMP into one PDF
- PDFs merged, reordered, reduced to selected pages, or rotated
- PNG, JPG, WebP, and BMP resized, center-cropped, rotated, compressed, or converted into common web image formats
The controls only expose operations that can be completed without pretending the browser is a full desktop editor. PDF text editing and dependable PDF recompression are deliberately absent: rewriting arbitrary fonts, forms, signatures, and embedded images without changing the document is a different problem from page-level editing. Every supported path has a browser test that opens a real fixture, performs the operation, and checks the resulting file—not just whether a button was clickable.
Your computer is the server
Local processing has an honest tradeoff. A large video can take time, use substantial memory, or fail on an older phone. The first media conversion also downloads a roughly 31 MB FFmpeg engine. That cost belongs in the interface, not in fine print.
Phones and computers also fail differently. Touch layouts need larger controls and a persistent save link; iPhone and iPad may open the result in Preview before “Save to Files.” Older Safari builds can reject an image through createImageBitmap, so the image path has a regular image-decoder fallback. Large-file recommendations are conservative and device-aware, but remain warnings rather than fake universal limits.
For everyday files, the exchange is worth it: no queue, no account, no advertising inventory, and no need to hand a private file to an unknown service. The browser is not merely displaying the tool; it is doing the work.
The result is one clear place, one honest button, and no need to guess where the file went or which download link is real.