Glass vs Stainless Steel Kettle: Which to Buy
By Tefal Singapore | Published: 2026-10-24
Category: Comparisons
Deciding between a glass or stainless steel kettle? We compare Tefal's Thermo Protect and Glass Kettle on safety, durability, and visibility to help you choose.
Quick answer
Choose a stainless steel kettle for durability and cool-touch safety, or a glass kettle if you prefer to see the water level and boiling action. Both materials have clear trade-offs.
Why material matters in an electric kettle
The material of your kettle affects not just looks but also heat retention, safety, and how easy it is to gauge water levels. Stainless steel is known for its toughness and insulation, while glass offers transparency and a modern aesthetic.
Safety and heat retention
Stainless steel kettles with double-wall insulation, like the Tefal Thermo Protect, stay cool to the touch even when boiling water inside. Glass kettles typically have a single wall and can become hot on the outside, so you need to handle them more carefully.
Visibility and convenience
A glass body lets you see the water level and watch the boil, which is helpful when filling or brewing tea. Stainless steel hides the water level, though many models include a window or indicator. The Tefal Glass Kettle's transparent body solves this naturally.
Trade-offs at a glance
- Stainless steel: durability and cool-touch safety: The Tefal Thermo Protect's double-layer insulation keeps the exterior cool, and the concealed heating element makes cleaning easy. The 1.5L capacity is slightly smaller than the glass option.
- Glass: visibility and larger capacity: The Tefal Glass Kettle holds 1.7L, so you boil more water per cycle. The transparent body shows the water level and boiling process, but the single-wall design means the outside gets hot.
- Heating performance: Both kettles use 1500W concealed elements for fast boiling. The stainless steel model has an on/off switch with indicator light; the glass model relies on its own switch (specs not detailed). Neither offers variable temperature control. If you need precise temperature for green tea or pour-over coffee, look for a variable-temperature kettle instead.
Product facts at a glance
- Tefal Thermo Protect 1.5L Kettle – Safe to Touch, 1500W Fast Heating, Easy to Use, Auto-off, 360 Rotation KO140A/KO1408: Full stainless steel inner body with double-layer insulation – Safe to Touch You can safely touch the exterior even during boiling, reducing burn risk around children or in busy kitchens.
Tefal Thermo Protect 1.5L Kettle – Safe to Touch, 1500W Fast Heating, Easy to Use, Auto-off, 360 Rotation KO140A/KO1408 - Tefal Glass Kettle 1.7L KI6058: Transparent glass body lets you monitor water level at a glance No need to open the lid or guess – you always know exactly how much water is inside, which is handy for precise tea brewing.
Tefal Glass Kettle 1.7L KI6058
Which one fits you?
Best for
- Households with children or anyone wanting a cool-touch exterior for extra safety – choose the stainless steel Tefal Thermo Protect
- Tea and coffee lovers who want to see the water level and enjoy watching the boil – choose the glass Tefal Glass Kettle
Not ideal for
- Those who need a larger capacity than 1.7L – both models are under 2L
- Users who want variable temperature settings – neither kettle offers that feature
