What Is a Document Feeder (ADF) on a Printer?
Last Updated:Quick answer: An automatic document feeder (ADF) is the tray on top of an all-in-one that pulls in a stack of pages and scans, copies or faxes them one at a time, so you are not lifting the lid for every sheet. Fifty sheets is the near-universal capacity on home and small office machines. What matters more than the number is what you are allowed to feed through it.
ADF vs Flatbed
The flatbed is the glass under the lid: one page at a time, but it handles anything you can lay flat — a book, a passport, a fragile original. The ADF is the stack feeder above it: fast and hands-off, but fussy about what it will accept.
Most all-in-ones have both, and the machine chooses automatically — put paper in the ADF and it uses the ADF. That is worth remembering when a scan comes out blank because the original was on the glass and the feeder had a stray sheet in it.
Simplex, Reversing and Single-Pass: The Terms Retailers Blur
| Type | What it does | Trade-off |
|---|---|---|
| Simplex ADF | Scans one side only | Two-sided originals need manual flipping |
| RADF (reversing) | Scans a side, flips the sheet, feeds it again | Duplex capable but slower and more jam-prone |
| Single-pass DADF | Two scan heads capture both sides in one pass | Fastest; found on better machines |
DADF simply means Duplexing ADF — it does not by itself mean single-pass. Canon proves the point by selling both on the same machine: the imageRUNNER ADVANCE DX 4700 offers a "Single Pass DADF-C1" at up to 200 sheets and a plain "DADF-BA1" at up to 100. If a listing just says DADF, it may still be a reversing feeder.
How Many Sheets, Really
Fifty is the answer almost everywhere in the consumer and small-office market. The Brother MFC-L2900DW, the HP Color LaserJet Pro MFP 4301 series and the Epson WorkForce Pro WF-M5899 all list 50-sheet feeders despite sitting in different price brackets. The real step up is copier-class hardware — Canon's departmental feeders run 100 to 200 sheets.
What You Should Not Put In It
Brother's instructions are blunt: do not load paper that is curled, wrinkled, folded, ripped, stapled, paper-clipped, pasted or taped, and do not feed cardboard, newspaper or fabric.
The spec sheet answers the two questions people actually have. On the Brother MFC-L2710DW the ADF accepts 60 to 105 g/m2 (16 to 28 lb) paper, 105 to 215.9 mm wide and 147.3 to 355.6 mm long. So:
- Card stock is out of spec by weight. Typical card stock is well above 105 g/m2. Use the flatbed.
- A standard till receipt is out of spec by width. Most are around 80 mm, below the 105 mm minimum. Use the flatbed.
- Photos do not belong in a feeder. Rollers mark them, and they are usually heavier than the limit anyway.
Heavier-duty machines have more room: Canon's Single Pass DADF-C1 handles 38 to 220 gsm, against 38 to 128 gsm on the cheaper DADF-BA1.
When It Starts Grabbing Two Sheets at Once
Two rollers do the work. The pickup roller feeds paper in; the separation roller exists specifically to stop multiple sheets feeding at once. Both are rubber, both wear, and both are consumable parts rather than faults.
They are user-replaceable. Epson, for example, states that the parts in its roller assembly kit need replacing after scanning every 100,000 pages, and its manual walks through swapping the pickup and separation rollers yourself. HP sells ADF roller replacement kits containing a roller and separation pad direct to customers. Before you order anything, though, clean the rollers — paper dust is the usual culprit and costs nothing to fix.
Frequently Asked Questions
What is an ADF on a printer?
An automatic document feeder: the tray that pulls in a stack of originals and scans, copies or faxes them one page at a time without you lifting the lid.
Does DADF mean single-pass duplex?
No. DADF means duplexing ADF. It may achieve that by flipping the page and re-feeding it. Only a single-pass DADF has two scan heads and captures both sides in one go.
Can I put card stock or receipts in the ADF?
Usually not. Brother's ADF spec on the MFC-L2710DW is 60 to 105 g/m2 and 105 to 215.9 mm wide; card stock exceeds the weight and most receipts are narrower than the minimum. Use the flatbed glass.
Why does my feeder grab two pages at once?
The separation roller is worn or dirty. Clean it first; if that does not fix it, roller kits are sold as user-replaceable parts.
How many sheets does a typical ADF hold?
Fifty on most home and small office all-in-ones. Copier-class machines run 100 to 200.
See Also
- What Toner Does the Brother DCP-L2540DW Use? (35-sheet ADF)
- How to Fix Paper Jams and Stop Them Coming Back
- What Is a Printer Driver?
- Find Ink by Printer Model
- Best Printers: Top Picks for Every Use Case and Budget
By William Elward, Founder of Castle Ink — 20+ years helping people solve printer and ink problems. Last updated August 24, 2026.
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