Underdial
Casio wins if you want near-indestructible utility, zero maintenance, and best-in-class features under $100. Seiko wins if you want mechanical depth, broader style options, and a watch that grows with you as a collector. Both are exceptional -- the right choice depends entirely on what you want from a watch.
Two Japanese brands. Both under $500. Both recommended constantly on every watch forum, Reddit thread, and beginner’s guide in existence. And yet Casio and Seiko are doing almost entirely different things — which is exactly why the comparison is worth making properly.
This isn’t a close horse race. These brands aren’t chasing each other. Choosing between them is really a question of what kind of watch person you are, or want to become.
A question we hear often: If low-maintenance reliability is your top priority and you have no particular interest in mechanical movements, Casio is the easy answer. The brand’s quartz movements are among the most accurate in the world at any price, and models like the F-91W or A168WA are essentially set-and-forget objects — a fresh battery every two to three years, no servicing, no winding, no thinking. The G-Shock line takes that philosophy further with shock resistance, world time, countdown timers, and depth ratings up to 200m baked into watches that cost less than a dinner out.
Seiko makes both quartz and automatic watches, and its quartz lineup is solid but rarely the point. The brand’s identity is rooted in mechanical watchmaking — the 4R36 automatic in a Seiko 5 Sports, the 6R35 in the Presage, the NH35 found across dozens of references. If you want a watch that winds itself on your wrist, rewards you with a visible rotor spinning through a display caseback, and connects you to a 140-year-old engineering tradition, Seiko earns that at prices starting around $150-$200.
The short version: Casio for utility-first, zero-complication ownership. Seiko for mechanical engagement, even at entry-level prices.
Here’s a direct comparison across the most popular models at comparable price points:
| Feature | Casio F-91W (~$15) | Casio G-Shock DW5600 (~$55) | Seiko 5 Sports SRPD (~$200) | Seiko Prospex Diver (~$350-$500) |
|---|---|---|---|---|
| Movement | Quartz (Casio module) | Quartz (Casio module) | NH36 Auto (Seiko in-house) | 4R35 / 6R35 Auto (Seiko in-house) |
| Crystal | Mineral | Mineral | Hardlex | Hardlex or Sapphire |
| Water resistance | 30m | 200m | 100m | 200m |
| Power source | Battery (~7 yrs) | Battery (~2 yrs) | Self-winding (automatic) | Self-winding (automatic) |
| Case material | Resin | Resin/composite | Stainless steel | Stainless steel |
| Accuracy | +/-15 s/month | +/-15 s/month | +/-25-45 s/day (typical NH36) | +/-25-45 s/day |
| Serviceable movement | No (module replace) | No (module replace) | Yes | Yes |
One stat worth noting: Seiko’s NH-series automatic movements typically run to +/-25-45 seconds per day from the factory, which is meaningfully less accurate than any quartz. If accuracy is your priority, Casio’s quartz modules win by a wide margin. That’s not a criticism of Seiko — it’s just a physics fact of mechanical movements at this price.
This one comes up a lot: People underestimate Casio because its entry prices are absurdly low. The F-91W retails for around $15, runs on a battery that lasts roughly seven years, keeps time to within about fifteen seconds per month, and survives the kind of daily abuse that would kill most fashion watches at ten times the price. That’s not budget watchmaking. That’s engineering precision applied to commodity manufacturing.
Move up to the G-Shock and the value proposition scales dramatically. The DW5600 series, typically available for $50-$70, offers 200m water resistance, shock resistance rated to survive a 10-metre drop, world time across 48 cities, a stopwatch, countdown timer, and an LED backlight — all in a case designed to international military and sports standards. According to Casio’s own specifications, the original G-Shock was developed in 1983 to survive a 10-metre free-fall and 10 atmospheres of water pressure simultaneously. Forty-plus years later, the core module philosophy hasn’t changed.
The premium Casio lines — Edifice, Oceanus, and the MR-G titanium G-Shocks — reach up toward and occasionally past $1,000, but even these represent extraordinary feature-per-dollar value. Where Casio loses points is in mechanical soul: no automatic movement, no display caseback, no rotor, no heartbeat sensation on the wrist. It’s a technology product, brilliantly executed.
Seiko’s real advantage is range. The brand produces everything from a $50 quartz field watch to a $900 Presage cocktail-inspired dress automatic, and the depth of the lineup means there’s almost certainly a Seiko that fits your style, wrist size, and budget without compromise. That breadth is genuinely unusual at this price tier.
The mechanical side is where Seiko has built its collector reputation. The NH36 movement powering most Seiko 5 Sports references is a refinement of a caliber Seiko has been making for decades. It hacks (stops the seconds hand so you can set time precisely), hand-winds (so you can top it up without wearing it), and is serviced at independent watchmakers worldwide for reasonable fees. When you factor in that mechanical watches can last generations with proper servicing — compared to quartz modules that are simply replaced at end-of-life — the long-term economics shift in Seiko’s favour for buyers who plan to keep a watch for fifteen or twenty years.
Seiko finishing is also a step above most competitors at this price. Even a $200 Seiko 5 Sports typically features alternating brushed and polished surfaces on the case and bracelet — a detail that signals genuine manufacturing investment, not cost-cutting assembly. That’s something Casio largely doesn’t pursue, because it’s not relevant to Casio’s utility-focused brief.
Readers frequently ask: The G-Shock vs Seiko 5 comparison is the most commonly made, but it’s not always the most useful one — because these two watches are targeting completely different buyers. The G-Shock is a tool designed to be indestructible and feature-rich. The Seiko 5 is an entry point into mechanical watch collecting. Comparing them is a bit like comparing a multi-tool to a quality chef’s knife. Both are useful; they’re just useful for different things.
A more meaningful comparison for sport watch buyers might be the Casio G-Shock GW-M5610 (~$100) versus the Seiko Prospex SRPD51 “Turtle” (~$380). The G-Shock adds Tough Solar charging and multi-band radio sync (atomic timekeeping accuracy) — genuinely impressive technology. The Turtle gives you a 200m-rated dive watch with a distinctive cushion case, NH35 automatic movement, and a design lineage going back to 1976. At these prices, the question is simply: do you want a precision tech instrument or a mechanical diver with real character? There’s no wrong answer.
If you’re building a collection rather than buying one watch, the best move is often one of each — a G-Shock for sport and travel, a Seiko automatic for everyday wear. Many enthusiasts land there naturally. Underdial can help you check whether a specific Seiko or Casio reference clashes with something you already own, or whether it actually fills a gap in your box.
Seiko. Clearly and without caveat.
Casio produces excellent watches, but the brand’s collector community is relatively narrow — centred on vintage G-Shocks, certain Edifice references, and limited regional releases. Seiko sits at the foundation of the global affordable watch collecting world. Read any online watch forum or scroll through recommendations for the best watches under $500, and you’ll see Seiko mentioned constantly — for good reason.
More practically, Seiko’s catalogue is full of references that interact meaningfully with the broader enthusiast conversation. The SKX007 (now discontinued but widely traded pre-owned), the Seiko 5 Sports, the Presage line, the Prospex dive series — these are all watches that collectors discuss, modify (the Seiko mod scene is enormous), and trade. When you own a Seiko, you’re part of an ongoing conversation. That matters if collecting is where you’re heading. Our guide to how to build a watch collection under $1,000 covers this in more depth.
Casio focuses on high-utility tool watches and entry-luxury through lines like Edifice and Oceanus: performance over brand markup. The Edifice line (typically $150-$500) is genuinely impressive engineering — solar charging, Bluetooth sync, lap memory chronographs, and tachymeter bezels in steel cases with sapphire crystals. If you commute by motorbike, travel frequently across time zones, or simply want maximum function in a smart-looking case, the Edifice EQB series competes with nobody in its price tier.
But here’s the honest take: above $300, Casio’s style appeal narrows significantly. The Edifice aesthetic — dense dials, multiple subdials, racing motorsport branding — is a specific flavour that enthusiasts either love or don’t. Seiko at $300-$500 offers dramatically more design variety, from the minimalist Presage cocktail dials to the aggressive Prospex Samurai to the retro-inspired Seiko 5 Sports.
The most common mistake new watch buyers make is stretching beyond their comfort zone because the internet told them a certain level is the minimum for a “real” watch. That’s nonsense. At $300-$400, both Casio and Seiko offer watches that are genuinely excellent. Choose by style first, then evaluate the specs.
Ask yourself these three questions:
1. Do I care about mechanical movements? If the answer is even a tentative yes, go Seiko. If you actively don’t want the mild complexity of an automatic, go Casio.
2. What’s my primary use case? Sport, travel, outdoors: Casio G-Shock wins on resilience and features. Office, everyday wear, social occasions: Seiko’s broader style range wins.
3. Am I buying one watch, or starting a collection? One watch: either works, buy what you like the look of. Starting a collection: Seiko gives you more to grow with, more to learn from, and more to trade or modify down the line.
If you’re genuinely torn and own a few watches already, Underdial’s wrist-size check and style audit can tell you in seconds whether the specific reference you’re looking at is a duplicate of something in your box — or whether it fills a real gap.
Is Casio or Seiko better quality? They excel in different areas. Casio leads in quartz accuracy, shock resistance, and feature density at low prices. Seiko leads in finishing quality, automatic movement engineering, and design variety. Neither is universally “better” — it depends on whether you value utility or craftsmanship more.
Which is better for a first watch — Casio or Seiko? Both are excellent first watches. Choose a Casio F-91W or A168WA if you want something effortless and essentially maintenance-free. Choose a Seiko 5 Sports if you want to start exploring mechanical watches and build a more enthusiast-oriented collection from day one.
Does Casio make automatic watches? Casio does not make traditional automatic mechanical watches. The brand focuses entirely on quartz, digital, and smart watch technology. If you want an automatic from a Japanese brand at a low price, Seiko and Orient are your primary options.
Which brand holds its value better, Casio or Seiko? Neither brand holds value strongly below $200, which is expected at this price tier. Above $300, certain Seiko references — particularly the discontinued SKX007 and some Prospex models — hold or slightly appreciate on the pre-owned market due to collector demand. Most Casio models depreciate predictably.
Can I wear a Casio G-Shock diving? Some G-Shock models are rated to 200m and suitable for swimming and recreational snorkelling, but they are not ISO 6425-certified dive watches. For actual scuba diving, a Seiko Prospex model rated 200m+ with a screw-down crown and unidirectional bezel is the appropriate choice.
Is Casio or Seiko better quality?
They excel in different areas. Casio leads in quartz accuracy, shock resistance, and feature density at low prices. Seiko leads in finishing quality, automatic movement engineering, and design variety. Neither is universally 'better' -- it depends on whether you value utility or craftsmanship more.
Which is better for a first watch -- Casio or Seiko?
Both are excellent first watches. Choose a Casio F-91W or A168WA if you want something effortless and essentially maintenance-free. Choose a Seiko 5 Sports if you want to start exploring mechanical watches and build a more enthusiast-oriented collection from day one.
Does Casio make automatic watches?
Casio does not make traditional automatic mechanical watches. The brand focuses entirely on quartz, digital, and smart watch technology. If you want an automatic from a Japanese brand at a low price, Seiko and Orient are your primary options.
Which brand holds its value better, Casio or Seiko?
Neither brand holds value strongly below $200, which is expected at this price tier. Above $300, certain Seiko references -- particularly the SKX007 and Marinemaster models -- hold or slightly appreciate on the pre-owned market due to strong collector demand. Most Casio models depreciate predictably.
Can I wear a Casio G-Shock diving?
Some G-Shock models are rated to 200m and are suitable for swimming and recreational snorkelling, but they are not ISO 6425-certified dive watches. For actual scuba diving, a true dive watch from Seiko's Prospex line (rated 200m+ with a screw-down crown and unidirectional bezel) is the appropriate choice.