All about S1P Files

The S1P file type is primarily associated with Keysight ADS.

S1P	File extension: S1P
	File type:	data file

What is an S1P file

S1P files mostly belong to Keysight ADS. S1P files are Touchstone format files that hold one-port scattering parameter data used in RF measurements. They provide precise information on the reflection characteristics of a device under test.

Format: A plain text file following the Touchstone standard.

Primary Use: Capturing one-port RF measurement data, such as reflection coefficients.

Vendor Origins: Generated by instruments like the Agilent PNA-X Network Analyzer, Keysight ADS, Rohde & Schwarz Network Analyzer, and NanoVNA-F.

FilExt.com notes: These files record frequency and complex data values in a structured format. The header often contains key metadata (e.g., frequency units, parameter format) that is critical for proper interpretation. They are used by specialized RF analysis and simulation software to assess circuit performance. For additional details and standards, refer to the Rohde & Schwarz website.

How do you open S1P files?

You need a suitable software like Keysight ADS to open an S1P file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your S1P file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a S1P file directly in the browser:. Just drag the file onto this browser window and drop it.

Online S1P Text Viewer

Choose your .s1p file to view

or drag and drop it here

Online File Viewer

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How to extract texts from S1P files or capture a screenshot to PDF, JPG, DOCX, TXT, ...

If you want to extract texts from S1P file or capture a screenshot, you can use our free Online S1P File Viewer:

To do this, click the button "Choose your .s1p file to view" on this page.
After your file is opened in browser,
click "Save as..." in the menu.
Then choose the file format (e.g. JPG, PDF, DOCX, TXT, ...) you want.
Your file will be converted and downloaded.

Programs that open and convert S1P files:

Keysight ADS
See the previous paragraphs to learn more about the main application. S1P files are often referred to as Keysight ADS data files because this type of file is primarily created or used by this software.
Sealed (PowerPoint Presentation) by SealedMedia
SealedMedia software integrates with existing business systems to deliver protection of valuable digital information. It enables complete control over who can use sensitive information and when. The originator can change rights to access and use a document even after it’s been delivered including revoking access. The Mime types used with this association are: application/vnd.sealed.ppt. The identifying characters used for this association are - Hex: 53 6F 66 74 53 45 41 4C 20, ASCII: SoftSEAL. Related links: Unsealer

S1P file format details:

A file format defines how the data in the file is structured. Often, the file format can be deduced from the file extension or the initial bytes (called the signature). However, different programs can use the same file extension, and file extensions can be assigned incorrectly. So you need a detailed analysis of a file to find out the format and the associated program. In the following you will find our evaluation of the S1P files:

The file type with the extension 'S1P' includes various formats for various programs. The following file formats are most commonly found in S1P files:

25% of all S1P files start with the bytes !Agilent , which are crucial for this file format. The contents of these files are easily readable with a text editor. S1P files are between 4 KB and 64 KB in size. The file type is relatively new. The files contain the following words: Date, Agilent Technologies, Port, !Data & Calibration Information, !Freq, Correction and !S1P File: Measurement: S11. Files like these are about auto, save and dipole.
15% of all S1P files start with the bytes # HZ S , which are crucial for this file format. These files are plain text, which means they can be viewed with any text editor such as Windows Editor, Nano for Linux, and TextEdit for macOS. The files are on average 14 KB in size and range from 7 KB to 400 KB. The following keywords are characteristic: Port, ! Rohde & Schwarz Vector Network Analyzer, Created, Rohde-Schwarz, freq, # HZ S RI R 50.00 and # HZ S DB R 50.00. The following filename is common: s11.s1p. Such files are related to bacon and indpaper.

All other S1P files (60%) have no uniform format, such as Keysight, Start and Rohde. They are often associated with port, mimo, antenna, load, sensor, short or egik. You can get all the details of your S1P file by dragging it onto this page or by clicking the button "Choose your .s1p file to view" above.

Technical Data for S1P File Extension

File classification:

Data

Identifier:

Hex: 53 6F 66 74 53 45 41 4C 20, ASCII: SoftSEAL (provided by TrID database)

Related files:

s2p, s3p, s4p, snp, s2p, sp1, s11, stone, zip, txt, npy, rar, spn, ssw, s14

Related links:

Unsealer

Mime type:

application/vnd.sealed.ppt

The following listing is compiled from the database produced by the 'Associate This!' program, selected data from the main FILExt database and file extension information submitted by users.

ProgramID: SealedMedia.ppt
EXEFile: %ProgramFiles%\Internet Explorer\iexplore.exe %1

an s1p data file is a special file format and should only be edited and saved with the appropriate software.

How to solve problems with S1P files

Associate the S1P file extension with the correct application.
Update your software that should actually open data files. Because only the current version supports the latest S1P file format. Search, therefore, e.g. on the manufacturer website after an available Keysight ADS update.
To make sure that your S1P file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .S1P file online - secure, fast, and no downloads needed.