WALTER (Web-based Analyser of the Length of Telomeres) is a web-based toolset for terminal restriction fragments (TRF) scan analysis. It is consisted of two tools: ScanToIntensity and IntensityAnalyser. ScanToIntensity tool is able to convert selected areas of TRF scan into intensity profiles while IntensityAnalyser tool analyses the resultant file from ScanToIntensity to provide a boxplot or a violin plot depiction of said profiles with a possible statistical analysis.

WALTER toolset is running on the servers of Core Facility Bioinformatics, CEITEC. Toolset development was supported by the Czech Science Foundation, project no. 18-07027S.

In case you have used our toolset, please do cite

Lyčka, M., Peska, V., Demko, M. et al. WALTER: an easy way to online evaluate telomere lengths from terminal restriction fragment analysis. BMC Bioinformatics 22, 145 (2021).

Links to tools:

Direct connection (calculations might take longer in case more people are using the toolset at the same time due to the waiting for other users' process to finish):

Servers might be occasionally under maintenance which will make the toolset unavailable.  In such occasion, we do recommend users to download the portable version.

Portable version of the WALTER toolset (Windows OS only):

If you are not able to access the toolset or have any other problems, suggestions or a feedback, please contact us on the e-mail:

Update information:


WALTER toolset has been published in the journal BMC Bioinformatics: 

WALTER: an easy way to online evaluate telomere lengths from terminal restriction fragment analysis | BMC Bioinformatics | Full Text (


WALTER toolset v2.0 launched (ScanToIntensity output from v1.0 is not compatible with IntensityAnalyser v2.0)

Changes in the new version


WALTER toolset v1.0 launched


Prof. Jiří Fajkus
Prof. Jiří Fajkus
Head of Research Centre, Research Group Leader Senior
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Miloslava Fojtová
Miloslava Fojtová
Senior Staff Scientist
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