Gas high-order harmonics generated (GHHG) by the nonlinear interaction of an intense ultrashort laser pulse with atoms or molecules are now used in many fields including atomic, molecular, plasma, and solid state physics. The interest in the generated radiation results from unique features like tunability over the extreme ultraviolet (XUV) and soft x-ray (SXR) spectral regions (reaching several keV), good beam quality, and ultrashort pulse duration down to the attosecond range. Currently many efforts are devoted to increase both the conversion efficiency of the GHHG process and thus the photon flux of the emitted XUV radiation. For this purpose ELI-ALPS are developing several GHHG beamlines. The main target of these beamlines is to provide the users of the ELI-ALPS facility with state-of-the-art attosecond pulses to perform pump-probe experiments with attosecond time synchronization between IR and XUV or XUV and XUV pulses. The under developement attosecond sources will operate at a repetition rate of 100 kHz and 1 kHz, using high-order harmonic generation in noble gases confined in either isolated attosecond pulses or short trains of attosecond pulses. The XUV radiation will be available in different spectral ranges (from 17 eV up to 90 eV) selected using different noble gases and metallic filters. The produced pulses and pulse-trains offered to the users will be properly characterized with respect to pulse duration, spectrum, photon number, spatial coherence and brightness. Further details about ELI-ALPS facility and the overview of the GHHG beamlines will be discussed at the conference.