Windows
Compatible applications
Quick Facts
Basic information about this file format
Extension
.FQ
File Type
FASTQ Sequence Format
Category
Data
Best first step
Use compatible software
Quick Summary
A practical overview of the .fq file format
The FQ file extension, commonly referred to as FASTQ, is a text-based file format widely used in bioinformatics for storing biological polymer sequences, typically DNA or RNA, along with their corresponding base quality scores. Developed originally by the Wellcome Trust Sanger Institute, it has bec…
File extension
.FQ
File type
FASTQ Sequence Format
Category
Data
Recommended action
Open with a trusted compatible app
How to open a .fq file
Start with a trusted app that supports this format
- Check the file extension carefully and confirm that the file name really ends with .fq.
- Use software that supports this file type. If one app does not work, try another compatible program for the same platform.
- Update the application if the file was created by a newer version of the software.
- Scan files from unknown sources before opening them, especially documents, archives, scripts, installers, and executable files.
What is a .fq file?
File extension details and usage information
The FQ file extension, commonly referred to as FASTQ, is a text-based file format widely used in bioinformatics for storing biological polymer sequences, typically DNA or RNA, along with their corresponding base quality scores. Developed originally by the Wellcome Trust Sanger Institute, it has become the de facto standard for storing high-throughput sequencing data from platforms like Illumina. A standard FQ file represents each sequence using four lines: a sequence identifier starting with the '@' character, the raw sequence letters (A, C, T, G, N), a separator line starting with '+', and a string of ASCII characters representing the Phred quality scores for each corresponding base. This format is essential for genomic workflows, enabling researchers to perform quality control, sequence alignment, and variant calling.
Software Compatibility
Programs that may open or work with .fq files
macOS
Compatible applications
Linux
Compatible applications
Mobile
Mobile applications
Can .fq files be converted?
Options for saving or exporting this file to another format
In many cases, a .fq file can be converted by opening it in compatible software and using an option such as Save As, Export, or Convert. The available output formats depend on the file type and the application used.
- Use the original software that created the file when possible.
- Check whether the application supports exporting to common formats.
- Be careful with online converters when working with private, business, or sensitive files.
- If conversion fails, the file may be corrupted, incomplete, encrypted, or not actually a .fq file.
Why can't I open a .fq file?
Common reasons this file type may not open correctly
Wrong software
The file may require a specific program that supports the .fq format.
Incorrect extension
The file extension may have been renamed manually, even though the actual file format is different.
Corrupted file
The file may be incomplete, damaged during download, or transferred incorrectly.
Outdated app
Your software may need to be updated before it can open newer versions of this file format.
Frequently Asked Questions
Common questions about .fq files
To open a .fq file, use software that supports this file format.
- Geneious Prime
- UGENE
- CLC Genomics Workbench
- Notepad++
- MacVector
Open the file in compatible software and look for options such as Save As, Export, or Convert. If no export option is available, the file may require a specialized converter or the original application that created it.
- Verify that the file extension is correct.
- Install or update compatible software.
- Try another application that supports this format.
- Check whether the file is corrupted, incomplete, or encrypted.
A file extension alone does not guarantee whether a file is safe or unsafe. Only open files from trusted sources, scan unknown files before opening them, and be especially careful with executable, script, archive, and document files.
File safety tips
Use caution with unknown files
Only open files from trusted sources. Before opening a .fq file, scan it with antivirus software, verify that the file extension is expected, and avoid running unknown executable, installer, macro-enabled document, or script files.