Live DSP Engine
Online Guitar Amp Simulator
Low-latency tube simulation with interactive tone stack and cabinet modeling.
Input 1
frets.in
Preset Channel
Gain1.2
Gate5
Bass5.5
Middle5.5
Treble6.75
Presence8
Volume9
Power
Pilot Light
Click "Refresh & Grant Access" to see device names.
Select your guitar interface or microphone. Multi-channel inputs are automatically summed to mono.
Signal Chain
THE CRUSH
Drive0
Tone5
Level5
NEBULA
Mix2.5
Decay2.5
Tone7
Expansion Slot
Plug in, select your interface, and flip the power toggle to ignite the tubes. Use the backlit LCD screen to browse presets.
The frets.in amp simulator is a browser-native guitar amp simulation built on the Web Audio API. Unlike many browser guitar tools that play back samples or route your signal through a cloud server, frets.in processes your guitar entirely in-browser with a real signal chain: noise gate, preamp gain stage, three-band EQ, presence filter, power amp simulation, and cabinet impulse response.
Connect any USB audio interface — Focusrite Scarlett, Behringer UMC, PreSonus AudioBox — select it from the input dropdown, and click the power switch to activate the signal chain. The LCD display lets you browse 16 presets tuned to specific styles and tones.
THE CRUSH drive pedal adds pre-amp saturation for heavier tones, while NEBULA provides room and plate reverb. Both can be dialed independently from the main amp controls.
The entire simulation runs client-side. Your audio is never transmitted or recorded. The amp sim works on any modern desktop browser with Web Audio API support — Chrome, Firefox, Edge, and Safari on macOS.
Frequently Asked Questions
What does the 'Gain' control do on the amp simulator?
The 'Gain' control on the frets.in amp simulator manages the amount of signal being pushed into the virtual preamp stage. Increasing the gain introduces harmonic distortion and saturation, which is the foundation of rock and metal tones. At lower settings, you get a clean, 'glassy' sound typical of jazz or country music. As you turn it up, the signal begins to 'clip,' creating a thicker, more compressed tone with increased sustain. In our DSP engine, this is modeled using a non-linear tube simulation that responds dynamically to your playing intensity, just like a real vacuum tube amplifier.
What is a noise gate and why do I need one?
A noise gate is a critical dynamics processor that mutes the audio signal when it falls below a certain volume threshold. This is essential for guitarists because pickups—especially single-coils—often pick up electromagnetic interference (hum) from lights and electronics. When you aren't playing, this noise can be very distracting, especially when amplified by high-gain settings. The frets.in noise gate intelligently filters out this background hiss while allowing your actual playing to pass through cleanly. By setting the threshold correctly, you can achieve 'silent' breaks between your notes for a more professional, polished sound.
What is cabinet IR (impulse response) modeling?
Cabinet IR modeling is a sophisticated digital process that replicates the sonic characteristics of a real guitar speaker cabinet, microphone, and the room they are in. A raw guitar amplifier signal is extremely 'fizzy' and unpleasant to listen to on its own. The cabinet modeling on frets.in acts as a complex filter that smooths out these harsh frequencies, providing the 'warmth' and 'thump' associated with a real 4x12 or 2x12 speaker box. Our engine uses high-resolution impulse responses to ensure that your browser-based tone has the depth and realism of a professionally mic'd studio amp.
How do I reduce latency when playing through the browser?
Latency is the slight delay between plucking a string and hearing the sound from your speakers. To minimize this on frets.in, ensure you are using a dedicated USB audio interface with its latest drivers installed. In your system or browser settings, try to set the 'Buffer Size' to a low value like 64 or 128 samples. Higher buffer sizes create more delay, while very low sizes increase CPU load. Additionally, ensure that 'Direct Monitoring' is turned off on your hardware interface so you only hear the processed signal from the browser, which prevents a confusing 'doubling' effect.
Do I need an audio interface to use the amp sim?
While you can technically use the frets.in amp simulator with a standard laptop microphone, we highly recommend using a dedicated USB audio interface for the best results. An interface provides a 'Hi-Z' (High Impedance) input specifically designed for guitar pickups, ensuring your tone is clear and full-bodied. Using a microphone often results in excessive background noise and poor frequency response, making the amp sim sound muddy or thin. Interfaces from brands like Focusrite, Behringer, or PreSonus are affordable and will provide a significant upgrade in tone quality and latency performance.
Can I use headphones with the frets.in amp simulator?
Yes, using headphones is actually the preferred way for many players to experience the frets.in amp simulator. Headphones provide an isolated listening environment that allows you to hear the subtle details of our cabinet modeling and reverb effects without room interference. When using headphones, ensure they are plugged directly into your audio interface rather than your computer's built-in jack to ensure the lowest latency. This setup is perfect for 'silent' practice at night, allowing you to enjoy cranked-up high-gain tones without disturbing your neighbors or family.
What are the best audio interfaces for browser-based guitar apps?
For browser-based guitar simulation on frets.in, we recommend any modern USB audio interface that supports stable, low-latency drivers. The Focusrite Scarlett series is a global standard known for its excellent preamps and reliability. The Behringer U-Phoria series offers a great budget-friendly entry point with dedicated Hi-Z inputs. For Mac users, the Universal Audio Volt or Apogee Jam are also fantastic options. Ensure your chosen interface has 'class-compliant' USB support, which allows it to work seamlessly with web browsers on both desktop and mobile devices without needing complex driver setups.
Why does my guitar sound fuzzy or buzzy?
If your tone sounds overly buzzy or 'digital,' it is often due to an incorrect input level. Ensure that your audio interface's gain knob is set so that the signal is 'green' (not 'clipping' or turning red) when you play your hardest. If the signal is too hot, it will create harsh digital distortion before it even reaches our amp simulator. Additionally, ensure that your instrument cable is of good quality and that you are not sitting too close to computer monitors or fluorescent lights, which can induce '60-cycle hum' in your guitar pickups.
Is the frets.in amp sim a real DSP simulation?
Yes, the frets.in amp simulator is a genuine Digital Signal Processing (DSP) signal chain running entirely in your browser via the Web Audio API. Unlike simpler tools that might just play back pre-recorded samples, our engine processes your actual guitar signal in real-time through multiple stages: a noise gate, a non-linear preamp gain stage, a three-band 'Tone Stack' EQ, a power amp simulator, and a convolution-based cabinet modeler. This architecture allows the amp sim to react dynamically to your playing style, volume knob adjustments, and the specific characteristics of your guitar.
What's the difference between this and a VST plugin?
A VST (Virtual Studio Technology) plugin is a standalone software component that must be hosted within a Digital Audio Workstation (DAW) like Ableton or Logic. The frets.in amp sim, while similar in its DSP complexity, is built using web-native technologies that allow it to run directly in a browser tab. This 'zero-install' approach makes it much more accessible for quick practice sessions or for players who don't want to manage complex plugin installations. While VSTs offer more integration for recording, frets.in provides a high-performance, portable alternative that works on any device with a modern web browser.
What does the 'Presence' knob do on the amp?
The 'Presence' knob is a high-frequency control that affects the power amp stage of the simulation. Unlike the 'Treble' knob in the EQ section, which adjusts the brightness of the preamp signal, the Presence knob boosts the very high frequencies (around 3kHz to 5kHz) and changes the 'attack' and 'definition' of the sound. Increasing the presence can help your guitar 'cut through' a mix and add a sense of 'air' or 'bite' to your tone. It is especially useful for adding clarity to high-gain metal tones or giving a 'sparkle' to clean jazz settings.
Can I record my guitar directly from the browser?
While frets.in does not currently have a built-in 'Record' button, you can easily record the audio output using several methods. On Windows, you can use 'Loopback' audio in software like Audacity or a DAW to capture the sound from your browser. Mac users can use tools like BlackHole or Audio Hijack to route the browser audio into a recording application. We are actively working on adding a native recording feature that will allow you to save your performances as high-quality WAV files directly from the amp sim page without needing any third-party routing software.
How do I use a drive pedal with the amp simulator?
The frets.in amp simulator includes a built-in virtual drive pedal called 'THE CRUSH.' This pedal acts as a 'pre-gain' boost that adds its own flavor of saturation before the signal hits the main amplifier. You can use it to 'push' a clean amp into a light overdrive or to add more sustain and grit to a high-gain lead tone. Additionally, because frets.in uses standard audio inputs, you can actually plug your real-world physical pedals into your audio interface before the computer, and the amp sim will respond to them just like a real amplifier would.
Does the amp simulator work on mobile browsers?
Yes, the amp simulator is compatible with modern mobile browsers on iOS and Android. However, for a playable experience on mobile, you must use a compatible USB audio interface (connected via a camera kit or USB-C adapter). Using a mobile device's built-in microphone for an amp sim is not recommended as it will result in extreme feedback and poor tone. If you have the right mobile hardware interface, you can enjoy a fully portable, professional guitar rig that fits in your pocket, making frets.in an ideal solution for traveling musicians or practicing on the go.
What are the presets based on?
The 16 presets in the frets.in library are meticulously tuned to replicate iconic guitar tones from across music history. For example, our 'Texas Flood' preset is inspired by the legendary blues-rock sound of SRV, while 'Purple Haze' captures the psychedelic fuzz of Jimi Hendrix. We also have presets dedicated to classic rock ('Back in Black'), modern metal ('Djentleman'), and ambient styles ('Nebula'). Each preset pre-configures the gain, EQ, cabinet modeling, and effects to give you an instant starting point for your favorite genre, which you can then fine-tune to match your specific guitar.