How to send a fax online
Sending a fax online replaces the machine, the phone line, and the busy signal with a web page. OnlyFaxes works entirely in your browser so there is nothing to download or install. You upload a document, type the recipient's fax number, and the service converts your file and transmits it over a real telephone connection to the other end. The whole process takes about a minute and costs nothing.
How to send a fax online: step by step
Open the fax tool
Go to the OnlyFaxes home page. The free fax tool loads right away with fields for the recipient number, your document, and an optional cover sheet. There is no account to create and no software to install. It works in any modern browser on any device.
Upload your document
Drag in a PDF or image, or click to browse your device. OnlyFaxes accepts PDF, JPG, PNG, WEBP, TIF, BMP, GIF, HEIC, and plain text files. Multi-page PDFs and multi-page TIFFs are supported, and every file is automatically converted into a clean, fax-ready layout at 200 DPI.
Enter the fax number and optional cover sheet
Type the recipient's fax number for the US, Canada, UK, or Mexico. The tool formats it for you. If the recipient expects a cover sheet, toggle it on and fill in the subject and message. You can pick from dozens of free cover-sheet templates.
Send and confirm delivery
Enter your email for the delivery receipt, then click Send Fax. OnlyFaxes transmits your document over the phone network and emails you the moment it is confirmed delivered. Most faxes arrive in under five minutes.
Troubleshooting
- Fax shows as failed or not delivered
- Double-check the fax number, including the country code. If the number is correct, the recipient's machine may be busy or turned off. Wait a few minutes and try again. Some fax machines have limited memory and reject long documents; try sending fewer pages at a time.
- Document looks blurry or cut off
- Faxes transmit at 200 DPI in a fixed page width. For best results, upload a clean PDF rather than a photo of a printed page. Make sure the content stays within standard letter or A4 margins. Avoid very thin fonts or fine-print text smaller than 10pt, which can become unreadable after fax transmission.
- Upload is rejected or takes a long time
- Check the file size limit (shown on the upload area). Very high-resolution images are resized automatically, but extremely large files may time out. Try converting the file to PDF first. If your document is a scanned image inside a PDF, the file may be much larger than it looks.
- Recipient says the fax is blank
- This usually means the document was scanned with a white-on-white issue or the PDF contains vector elements the recipient's machine cannot render. Preview your fax on the OnlyFaxes page before sending to confirm the content is visible. If the preview looks correct, the issue is likely the recipient's machine.
Frequently asked questions
Do I need a fax machine to send a fax online?
- No. Online faxing sends your document over the internet to the recipient's fax machine or fax line, so you never touch a physical machine. The only equipment you need is a phone, tablet, or computer with a browser.
Is sending a fax online free?
- Yes. OnlyFaxes lets you send faxes for free with no signup. A dedicated number is available if you need your own line, higher page limits, or fax-to-email receiving.
What file formats can I fax?
- OnlyFaxes accepts PDF, JPG, PNG, WEBP, TIF, BMP, GIF, HEIC, and plain text files. Multi-page PDFs and multi-page TIFF files are fully supported.