Piece count gets treated as the main difficulty indicator for jigsaw puzzles, but two other factors genuinely change how hard a puzzle is to actually complete.
Piece count alone doesn't determine difficulty
A puzzle's image content has as much effect on real difficulty as its piece count. An image with large, distinct color blocks and clear focal points is meaningfully easier to sort and assemble than an image with the same piece count but a lot of repetitive texture, similar colors throughout, or a busy pattern with few clear reference points — a 500-piece puzzle of a detailed, uniform starry sky can be considerably harder in practice than a 1000-piece puzzle of a few large, distinctly colored objects.
Cut style affects both feel and effective difficulty
Ribbon cut puzzles have pieces arranged in straight, grid-like rows and columns, making edge and pattern alignment more predictable. Random cut puzzles vary piece size and shape throughout, without the grid regularity, generally considered a more traditional, sometimes more challenging jigsaw experience since pieces don't follow a repeating pattern. Neither is better — the choice mostly comes down to personal preference for how predictable or varied the piece shapes feel while working.
Piece thickness and material affect the feel of assembly and durability for reuse
Thicker, sturdier pieces feel more substantial to handle and hold together better if a puzzle is meant to be occasionally reassembled or handled by different people over time. Thinner, more cheaply made pieces can bend or fray at the edges with repeated handling, which matters more for a puzzle expected to be worked on over an extended period or by multiple people, rather than completed and disassembled quickly in one sitting.
Puzzle glue and display frames are a real, separate consideration for finished puzzles
For a completed puzzle meant to be preserved and displayed rather than disassembled, puzzle-specific glue (applied evenly across the front, sometimes the back as well for structural support) holds the assembled pieces together permanently — a different product from general craft glue, formulated to dry clear and not warp the paper puzzle pieces. A separate display frame, sized specifically to the finished puzzle dimensions, is worth planning for before starting if the intention from the outset is to preserve and display the completed piece.
The one thing people forget
Check that a puzzle is actually complete — missing pieces are a real, documented occurrence, particularly with secondhand or previously opened puzzles — before investing significant time in a large, complex puzzle. Working through hundreds or thousands of pieces only to discover a missing piece near the end is a common and genuinely frustrating experience that a quick early piece count check can sometimes catch in advance.