Our take
Brother's U.S. page identifies the MFC-7840W as a discontinued monochrome laser all-in-one with print, copy, scan and fax. The page rates output up to 23 pages per minute and lists a 35-sheet ADF, a 250-sheet tray and built-in wireless networking. The checked sources do not establish automatic duplex or Ethernet for this exact configuration. That leaves it as a useful wireless fax MFP candidate for a small office, but not a safe match for a required automatic-duplex workflow or a wired-network specification.
A small office needing wireless monochrome printing, fax and an ADF, with no hard requirement for automatic duplex or wired Ethernet..
Look elsewhere if automatic duplex, Ethernet, a stated monthly workload, color printing or current product availability is required.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- Brother lists print, copy, scan and fax in one monochrome device.
- Built-in wireless allows placement without assuming an Ethernet connection.
- The 35-sheet ADF and 250-sheet tray support everyday document handling.
What to weigh up
- Automatic duplex is not established for the exact MFC-7840W and should not be inferred from its W suffix.
- Ethernet and a recommended monthly volume are not established in the reviewed page.
- Brother marks the model discontinued; an individual unit's condition and supplies need separate checking.
Specifications and exact model details
The key details
| Model covered | MFC-7840W |
|---|---|
| Main functions | Monochrome print, copy, scan and fax |
| Print output | Up to 23 ppm; 35-sheet ADF and 250-sheet tray |
| Two-sided printing | Built-in wireless; duplex and Ethernet details unknown |
Performance figures are manufacturer claims. Source checked October 14, 2026. Regional models and included accessories can differ.
Full review: how the features affect your choice
What the features mean for you
What does this wireless MFP do?
Brother identifies the MFC-7840W as a monochrome laser all-in-one that prints, copies, scans and faxes. This suits a small office where paperwork arrives by fax and users need to digitize pages without a separate scanner. Output remains black-and-white, so it is not the right answer for color documents. The 35-sheet ADF gives a straightforward way to load multiple originals, while the source does not establish advanced duplex scanning or cloud integration.
How does wireless placement help?
Brother lists built-in wireless networking on the exact MFC-7840W. This can help place the printer where a network cable is unavailable, while the model's MFP functions remain accessible within the intended wireless setup. The checked product page does not establish Ethernet, so do not assume that a W model also has a wired network port. Confirm supported security and driver needs for your office, especially when connecting an older device to a current network.
Will the ADF and tray fit the daily paper flow?
The product page lists a 35-sheet ADF and 250-sheet main tray. The ADF handles a stack of originals for fax or scan, while the tray holds print stock; one capacity does not replace the other. This is a moderate desktop arrangement for a small office rather than a high-capacity workgroup feeder. If several people share the machine or routinely process long stacks, compare a model with a larger ADF and a documented workload range.
Is two-sided printing automatic?
Brother's checked page does not establish automatic duplex for the MFC-7840W. Do not infer page turning from the W suffix or from specifications for another MFC-7840 variant. The matching profile keeps both automatic and manual duplex unknown until exact documentation confirms them. If two-sided output is a hard requirement, choose a model whose exact configuration explicitly lists the feature. This precaution matters because paper handling changes daily effort and cannot be assumed from the all-in-one role.
What workload guidance is available?
The reviewed Brother page provides speed and tray information but does not establish a recommended monthly page range. Those specifications do not show how much printing Brother considers appropriate as a routine. Keep the monthly values unknown and use the machine's role, wireless connection and document feeder to judge whether it suits a light office. If workload planning is important, prefer an exact model with a published recommended range instead of converting the 23 ppm rating into a monthly estimate.
What should be checked for a discontinued unit?
Brother marks the MFC-7840W discontinued. That status does not establish the condition of any current offer, remaining supplies, seller return terms or driver support for a particular computer. Check the full MFC-7840W label, confirm wireless setup, and inspect the ADF and scanner path. Do not substitute a nearby MFC-7840 configuration with different suffixes or interfaces. The exact model identity is especially important when a used listing uses a shortened product-family name.
Compare for your needs
Choose the MFC-7365DN for confirmed automatic duplex and Ethernet, or the HP M130fw when a published monthly range is important.
Find the undefined that fits you.
Tell us what matters. We’ll help you weigh the options.
Before you buy
Does the MFC-7840W include fax?
Yes. Brother lists fax alongside print, copy and scan on the exact MFC-7840W page.
Can it connect over Wi-Fi?
Yes. Brother identifies built-in wireless networking for the MFC-7840W.
Does this model have automatic duplex or Ethernet?
The checked exact-model page does not establish either feature, so verify before treating them as requirements met.
Where can I check the current price?
Use the Amazon link for current offers. Check the exact model, seller, product condition, delivery, and return terms. This page does not display a live price or confirm stock.
Sources and review basis
Sources & review basis
We use the linked product documentation for the features above. Our suitability notes and buying advice are editorial judgments based on those features, not measured performance results.
- Brother U.S. MFC-7840W product page ↗ — checked October 14, 2026.
- Brother U.S. MFC-7840W exact model, functions, speed, ADF, input and wireless page ↗ — checked October 14, 2026.
- Brother U.S. MFC-7840W support page and discontinued model identity ↗ — checked October 14, 2026.
The decision
The MFC-7840W suits wireless mono fax and scanning when duplex, Ethernet and workload details are not hard requirements.
Is it the right fit?
Check the exact model and today’s offers on Amazon.