For IT directors, senior executives, and mobile sales teams, the choice of a professional smartphone is no longer limited to connectivity alone. Screen size has become the top criterion for mobility productivity. Reading contracts, analyzing complex dashboards, data visualization, or intensive multitasking: here is our selection of the 5 best "large format" terminals tested against B2B requirements in 2026. The Samsung Galaxy S25 Ultra is the ultimate mobile office for executives and demanding fleets. While the general public sees it as the king of multimedia, IT directors will see it mainly as a formidable productivity tool. With its lightweight titanium chassis (218 g), an AI-optimized chip, and a record software durability (7 years), the S25 Ultra establishes itself as an Android standard for the enterprise. Its massive 6.9-inch screen, protected by Gorilla Armor 2 glass, offers exceptional brightness measured at 2348 cd/m² and an anti-reflective treatment. This ensures perfect readability of dashboards and legal documents, even in direct sunlight on the field. The large surface makes full sense with the native integration of the S Pen, the ideal precision tool for electronic signatures and annotation of complex contracts on the move. The Samsung Galaxy S26 Ultra is a production tool designed for visual privacy. Facing the demands of hybrid mobility, Samsung's new flagship abandons titanium for aluminum to better dissipate the heat of the Snapdragon 8 Elite Gen 5, while betting on a breakthrough innovation to protect displayed data. The major innovation for professionals is the native Privacy Display. This system modifies the arrangement of the pixel matrix to restrict viewing angles on command, neutralizing visual hacking in public transport without altering the user experience on this large diagonal. It offers more than 26 hours of battery life and fast charging at 60 W, but lacks native Qi2 magnetic charging and has ergonomic issues due to a prominent photo island. The Oppo Find X9 Ultra is the flagship smartphone for visual expertise. Powered by a record silicon-carbon battery of 7050 mAh and a dual 200 Mpx optical sensor, this terminal is tailored for mobile experts and inspection technicians requiring massive autonomy and exceptional image capture. Its large 6.82-inch AMOLED LTPO screen offers first-rate visual comfort with factory colorimetric precision, eliminating the need for manual recalibration. However, its brightness is capped at 1243 cd/m², which requires adapting its viewing angle during use under direct strong sunlight. It offers 27 hours of battery life and 6 years of security patches, but has a heavy weight and non-certified facial recognition. The Samsung Galaxy S25+ is the alliance of Snapdragon 8 Elite and AI for fleets. Less expensive and lighter than the Ultra model, the Galaxy S25+ makes a spectacular leap in terms of autonomy. It is the choice of rationality, an ideal candidate for commercial fleets and executives in constant travel seeking the perfect balance. The S25+ offers the generous workspace of a 6.7-inch AMOLED screen, allowing two professional applications to be displayed side by side without compromising readability. It maintains a thickness of 7.3 mm and a weight of 190 g, offering all the comfort of reading a large screen without the physical constraints of the "Ultra" or "Pro Max" models. It offers 25 hours of autonomy, but has limited wired charging and telephoto limitations in low light. The Apple iPhone 17 Pro Max is the mobile control tower for executives. With an autonomy nearing 30 hours, an oversized A19 Pro chip and 12 Go of RAM, the iPhone 17 Pro Max is no longer just a smartphone: it is a credible alternative to a laptop for professionals in constant motion and data-intensive workflows. Its 6.9-inch LTPO OLED screen offers maximum workspace for handling large data volumes or mockups. Its flagship feature is a vertiginous brightness of 2930 cd/m², which completely eliminates visual fatigue, even when consulting 4K streams outdoors. It offers more than 29 hours of autonomy, but has a very long charging time and a high acquisition cost. For executives and intensive workflows, the Samsung Galaxy S25 Ultra and iPhone 17 Pro Max are top choices. The 6.9-inch diagonal establishes itself as the absolute standard for decision-makers. The S25 Ultra will shine in fleets requiring strict MDM integration and the use of the stylus for document validation. The iPhone 17 Pro Max will appeal to parks already under the Apple ecosystem thanks to its delirious autonomy and ultra-bright screen. For data protection in mobility, the Samsung Galaxy S26 Ultra is indispensable. Its material privacy filter (Privacy Display) integrated directly into the large secure screen secures the reading of contracts or financial statements in transport and co-working spaces, without requiring third-party accessories. For commercial fleets and ergonomic compromise, the Samsung Galaxy S25+ is the rational choice. With its 6.7-inch screen offering excellent readability while keeping the weight under 200g, it offers the workspace needed for mobile CRM without imposing the physical constraints of the "Ultra" or "Pro Max" models. Its 7-year support guarantees optimal amortization for large deployments. For mobile expert profiles and technical imaging, the Oppo Find X9 Ultra is the ideal terminal. If your profession requires high-precision visual readings and perfect colorimetry, the Find X9 Ultra and its 6.82" screen is the ideal terminal. Its massive battery allows it to last more than two days in the field, despite an encumbrance that limits it to very specific niche uses.