How to convert text, photos and spreadsheets into the files a form accepts

Start with what the form accepts

An upload form usually prints its rules next to the button: the formats it takes, the largest file it allows, and sometimes how many pages or what pixel size. Read those first. Converting a file into a format the form never listed only moves the refusal one step later.

Most forms that handle documents accept PDF. Most that handle photos accept JPG, and many accept PNG. Fewer accept WebP, HEIC, plain text or a spreadsheet, even though those are the formats people actually have. The work in this guide is turning what you have into what the form lists, without changing what the file says.

A text file into a PDF

A .txt file has no page size and no font. It is only characters and line breaks, and it does not even say how those characters are encoded: a file saved by an older Windows program and one saved by a modern editor can hold the same letters as different bytes. The WHATWG Encoding Standard describes the encodings a browser knows how to read.

TXT to PDF works out which encoding the file uses, then puts every line on the page in the order it is written. A blank line stays blank. A line too long for the page wraps rather than running off the edge, and a tab becomes four spaces. If a character has no shape in the PDF’s font, it is replaced and the result line counts how many, so you know to check them.

This is the right tool for notes, logs, a plain-text statement, or a cover letter written in a text editor. It is the wrong tool for a document that already has formatting, such as a Word file, which keeps its headings and spacing better through Word to PDF.

A WebP or HEIC photo into a PDF

WebP is an image format made by Google for the web, described in its WebP documentation. Browsers save it when you right-click a picture on a page, so it turns up in downloads folders all the time. HEIC is the format recent iPhones use for photos. Both make small files for their quality, and both are refused by forms that list only JPG, PNG or PDF.

WebP to PDF and HEIC to PDF put each photo on its own page. Choose several photos, drag them into order, and they become one PDF, which is what a form asking for “all pages in one file” needs. The photo is decoded and placed without a second lossy pass, so it is not made blurrier on the way.

If the form wants a picture rather than a document, convert to JPG instead and then check its pixel size and file size against the form’s rules.

A spreadsheet into a PDF or a CSV

An .xlsx workbook is a ZIP of XML parts, defined in the Office Open XML standard, ECMA-376. It can hold many sheets, formulas, colours and hidden rows, and a form rarely wants all of that.

For a person to read, Excel to PDF lays each sheet out on pages, with the header row repeated at the top of every page and a wide sheet turned to landscape. Columns too wide even for landscape are left out, and the result says how many, so you can decide whether to tidy the sheet first.

For a system to import, CSV is usually what it wants. CSV holds one table of values and nothing else, as described in RFC 4180. A workbook with five sheets has five tables, so Split Excel writes each sheet as its own CSV file and packs them into one ZIP. Formulas arrive as the values they last showed, which is what an import expects.

Check the result before you upload

Open the converted file before you send it. For a PDF, scroll every page: is anything cut off, is the text the right way up, are the photos in the right order? For a CSV, open it in a spreadsheet and check that the columns line up under their headings and that numbers such as phone numbers or reference codes kept their leading zeros.

Then check the file size against the form’s limit. If it is too large, compress the PDF or resize the photo before converting, and aim a little under the limit rather than exactly at it.

Keep the original. A converted copy is easy to make again; the source, especially a photo or a workbook with formulas, is not.

Why the conversion happens on your device

Every tool linked here runs in your browser tab. The file is read from your disk into the page, converted there, and handed back as a download. It is never sent to FileGizmo or to anyone else, and the site’s security policy limits what the page is even allowed to connect to. For a payslip, a lease or an ID scan, that is the difference between converting a file and handing a copy of it to a stranger.