Comparison

Smith Charts vs RF toolbox

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Smith Charts

Design matching networks, analyze device parameters, and compute stability circles with this interactive tool. Supports S parameters, various components, and offers advanced engineering features for RF design. Available in dark mode and exportable to PDF.

Highlights
  • Interactive Smith chart with drag and zoom
  • Design matching networks with various components
  • Compute stability, equi gain, and noise circles
  • Import S parameters from Touchstone files
  • Export designs to PDF, image, or file
  • Dark mode support
  • Ruler for wavelength measurement
Features
Read full description

A great experience of the Smith chart. Also in dark mode. Design matching networks, insert S parameters and convert them, or import from touchstone file. Compute stability circles, equi gain and noise circles.  Easy interaction with the Smith chart. This chart can easily replace a physical one, making its use much faster. Smith chart interactivity: - Works on iPhone, iPad and Mac (on Apple Silicon). - Drag and zoom in the chart. - Create multiple Smith Charts and name them. - Switch easily between input and output planes. - Use a ruler and drag it to obtain the wavelength toward generator of a point on the chart, instantly. - Tap the chart to show the coordinates in algebraic notation, you will see also magnitude and phase of that location, and the corresponding impedance. - Insert circles by hand; modify the radius dragging a circle to keep the center in place, or press to translate them and modify the radius keeping the opposite side in place. Then use the padlock button to disable interaction of gestures with circles. - You can also insert a custom circle and a segment in the input and in the output plane, defining its center and radius in a textfield. - Export to file, image or PDF Advanced tools for engineering: Matching networks: - Choose electronic components to design a matching network for your device. - Available components are: L, C, R, Z and lines (transmission line, parallel or series stub, open or shorted). - For each component it is possible to specify the parasites. - For transmission lines, it is possible to choose between Z0, K or L, C representations, and converting between the two (also for parasites). - Tapping on a component it is added to the network and the impedance seen from your device toward the matching network is shown on the smith chart. - You can create a matching network both for input and output planes of the device. - Each network has its own termination (source or load), which can be a one port device or a two ports device where you can choose a termination for the second port. - Each termination can be defined by network parameters (S, Z, Y or h) and the parameters can be imported from a touchstone file. - Components supported: Resistor, Capacitor, Inductor, General impedance (R+jX), Transmission line, Parallel stub, series Stub (both shorted or open). - Each component can be cascaded in series or in parallel, no limits of components. - You can choose a frequency for the impedance calculation and a frequency span for the plot on the Smith Chart. - For S parameters, you can specify a dedicated characteristic impedance, the tool will renormalize the Γ of that termination to be correctly shown on the Smith chart, when the smith chart is defined on a different characteristic impedance. Device analysis: - You can insert the following parameters of a device: network parameters (S, Z, Y or h), specifications (Ga, Gp, Gt, NF), noise data (gamma s optimum noise, minimum NF, rn) and the input/output reflection coefficients. - You can convert network parameters (S, Z, Y, h), and the port type (Γ, Z, Y). - While you are inserting data, you will see the computed results appearing on the chart and on the relative fields. - Results representable on the smith chart: input/output stability circles, power gain and noise circles (equiGa, Gp, Gt, NF circles), reflection coefficients towards load and source and optimum power coefficients. - Other results: obtained power gains and noise (Ga, Gp, Gt, NF) and stability (D, K, kind of stability). - You can display on the Smith chart the input impedance of your component versus frequency (as a function of load impedance) when importing a touchstone file. - For S parameters, you can specify a different characteristic impedance and the tool will automatically convert it to the one defined for the Smith chart, it will let you know the new renormalized parameters.

About

RF toolbox

Features
Read full description

RF Toolbox — All-in-One RF Engineering Calculator & Design Suite RF Toolbox is a practical, field-ready app built for RF engineers, students, and radio hobbyists who need fast, reliable calculations and design utilities in one place. From impedance matching and transmission line work to filter and attenuator synthesis, RF Toolbox helps you move from idea to implementation with less friction. KEY FEATURES Impedance & S-Parameter Tools • Smith Chart utilities for impedance visualization and matching workflows • S11 parameter / reflection analysis support • Reflection coefficient and VSWR calculators Matching Networks • L, Pi (π), and T matching network calculators • Stub tuner tools for transmission-line matching • Filters (Passive & RF) • RC and RL passive filter calculators • LC low-pass prototypes: Butterworth and Chebyshev (up to 8th order) • Microstrip filters: band-pass and band-reject (notch) • RLC Networks • RLC series and parallel calculators for resonance and frequency behavior Attenuators • Pi (π), T, and Bridge-T attenuator calculators for common RF pad designs • Cascaded Networks • Cascaded network calculations for chained RF blocks and stages Antenna & Propagation • Antenna design utilities (core RF design helpers) • Path loss calculators • Friis link budget calculator • Power density calculator • Radar maximum range calculator Component Toolkits • Inductor design: air-core, spiral, and multi-layer air-core • Resistors: SMD code, color code, and series/parallel network calculator • Capacitors: SMD code and series/parallel network calculator DESIGNED FOR SPEED AND ACCURACY RF Toolbox is organized for quick access—open the tool you need, enter values, and get results immediately. Whether you’re prototyping a matching network, checking VSWR, sizing an attenuator, or running a quick link budget, RF Toolbox keeps your workflow efficient. Download RF Toolbox and keep essential RF design tools in your pocket.

Screenshots

Smith Charts4 screens
RF toolbox4 screens

Verdict

The call

The clearest difference is price: RF toolbox at Free against Smith Charts's $3.99. RF toolbox also leads on iOS requirement (13.0 vs 15.0). Smith Charts's advantage is in-app purchases (none vs 1) and update cadence (every 3 weeks vs every 6 months). On ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

RF toolbox is free to download; Smith Charts costs $3.99 up front. RF toolbox sells 1 one-off in-app purchase. Smith Charts asks for nothing beyond the download.

UpkeepUpdate frequency

Smith Charts ships an update every 3 weeks, RF toolbox every 6 months. The most recent releases landed on September 21, 2026 and September 9, 2026 respectively.

Scorecard4 real differences · 6 level
Smith Charts versus RF toolbox: the parameters behind the verdict, then further details
ParameterSmith ChartsRF toolbox
Price$3.99Free — better
Rating3.7 (3 ratings) — better—
Positive reviews66.7% of reviews—
Number of ratings3 — better—
Update frequencyEvery 3 weeks — betterEvery 6 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.013.0 — better
Further details — not scored
Size24 MB28 MB
Age rating4+4+
DeveloperEdoardo OrzesAnas Abubakar

In-app purchases

None

Smith Charts

No in-app purchases

1 purchases

RF toolbox

One-time1
  • upgrade to pro$3.99

Questions

Is Smith Charts free?
Smith Charts costs $3.99, with no in-app purchases.
Is RF toolbox free?
RF toolbox is free to download, with in-app purchases available.
Do Smith Charts or RF toolbox have ads?
Neither Smith Charts nor RF toolbox shows ads.
Which is updated more often, Smith Charts or RF toolbox?
Smith Charts ships an update every 3 weeks, and RF toolbox every 6 months. Most recently, Smith Charts was updated on September 21, 2026 and RF toolbox on September 9, 2026.

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