About nanofile
The file compressor that never uploads your files. This page is the long version: what it does, how it is built, who builds it, and what it deliberately will not do.
What it is
nanofile is a free file compressor for 36 formats, plus a set of converters for the pairs people most often need. Images, PDFs, Office and OpenDocument files, audio, fonts, ebooks, 3D meshes, markup and archives all have their own tool, and dropping a file on the home page sends it to the right one.
It reads the bytes rather than the extension, so a photo your phone named .jpg that is really a HEIC still finds the tool that can open it. Every tool can compress to a target file size, work through a batch, and hand the results back one at a time or as a ZIP.
Why nothing is uploaded
Every compressor here runs in your browser. The file is read into memory by the page, the work happens on your own processor, and the result is written back to your disk without any of it becoming a network request. There is no upload endpoint in the application, no storage bucket behind it and no queue.
This is not a promise about what we do with your files, it is a description of a site that never receives them. That distinction is the whole reason the site is built this way. A compressor that uploads has to be trusted; one that cannot upload does not.
What makes it possible is that browsers now ship most of a compression toolchain already, and what they do not ship can be compiled to WebAssembly and sent down with the page. The image tools use the browser's own encoders on the fast settings and MozJPEG, libwebp and oxipng on the slower ones. PDFs are rebuilt with pdf-lib, audio is re-encoded through mediabunny, fonts are subset and repacked, and archives are rewritten in place. A page only downloads the codec it actually needs, so the JPG tool never fetches the PDF machinery.
There is one consequence worth stating plainly: speed depends on your device, not on our hardware. A large file on an old phone takes longer than it would on a server. That is the trade, and we think it is the right way round.
Who builds it
nanofile.io is operated by Convert Case Ltd, a company registered in England and Wales and based in Hull. The tools are older than the company: Convert Case launched in 2006 and the same rule has applied to everything since, this site included. A tool should work immediately, without an account, and should not be a funnel to something else.
The other sites we run, in case one of them is the tool you actually wanted:
- Text tools at convertcase.net
- Video at vidshift.io
- Ebooks at ebook.tools
- Notes at onlinenotepad.net
How it stays free
Compression costs us nothing per file, because it does not happen on our machines. What the site costs is the hosting of some static pages, which is cheap and does not scale with how much you compress. So there is no account to create, no watermark, no daily limit and no paywall in front of the good settings.
The one thing that does leave your browser is anonymous usage analytics, which tell us which tools people use and which ones fail them. Every event is listed, with what it carries, on the privacy policy. Nothing derived from a file's contents is ever included, and that rule is enforced by a test rather than by good intentions.
What it will not do
- No API. There is no server-side compression to call, so there is nothing to invoke remotely. This is a property of the design rather than a feature we have not got to.
- No video. Video is a different problem with different constraints, and it gets its own site: vidshift.io. Drop a video here and we will say so and point you there rather than pretending.
- No unzipping. The ZIP tools create archives and rebuild existing ones smaller. Extracting what is inside somebody's archive is a different job and your operating system already does it.
- No claims we cannot hold. Where a compressor cannot honour a setting, the page says so instead of showing a switch that does nothing, and where a saving has no honest range to quote, it says that too.
Questions and requests
Who is behind nanofile?
nanofile.io is built and run by Convert Case Ltd, a small British company. The tools go back further than the company does: Convert Case launched in 2006 and has been free ever since. The registered details are in the footer of every page.
How is it free?
The compression runs on your own processor, so a file costs us nothing to handle no matter how large it is. There are no servers to pay for per file, which is why there is no account, no watermark, no queue and no daily limit. The site carries analytics and links to our other tools, and that is the whole of it.
What is the catch with client-side compression?
Speed depends on your device rather than ours, so a very large file on an old phone is slower than it would be on a server. In exchange, nothing is uploaded, nothing is queued behind other work, and the tools keep running with the network disconnected once the page has loaded.
Do you have an API?
No, and there cannot be one. There is no server-side compression to call: the codecs run in the browser, so there is nothing to invoke remotely. Anything offering a nanofile API is not us.
Can I ask for a format?
Yes. Email hello@convertcase.net and say which format and what you are trying to do with it. The site is format-routed, so adding one is a new page and an engine rather than a rewrite, and requests are how the roadmap gets ordered.
Anything else, including a format you want and a bug you have found, goes to hello@convertcase.net. Mail sent from the links on this site arrives with "nanofile" as the subject, which is what keeps it out of the pile for the company's other sites.
Registered in England and Wales. Company number: 11614495.
Registered office address: C4DI @TheDock, 31-38 Queen Street, Hull, England, HU1 1UU.