Choose the Formlabs Form 4 for a new professional resin purchase or an upgrade when recurring deadlines and operator time can repay its faster current workflow. Keep or consider a Form 3+ only when an already-qualified process or a verified used discount survives a full machine-condition, consumables, support, wash, cure, labor, and failed-job audit.
The published average-speed comparison is 40 mm/hour for Form 4 versus 11 mm/hour for Form 3/+, but accepted output is the real metric. Form 4 also lists a 20.0 x 12.5 x 21.0 cm volume versus 14.5 x 14.5 x 19.3 cm for Form 3/+. It is larger overall, though the older machine remains wider on one nominal planar axis.
| Upgrade question | Form 3+ | Form 4 | Decision rule |
|---|---|---|---|
| Published average speed | 11 mm/hour across materials | 40 mm/hour across materials | Benchmark the exact resin and supported production part through inspection |
| Build envelope | 14.5 x 14.5 x 19.3 cm; 4.05 L listed | 20.0 x 12.5 x 21.0 cm; 5.25 L listed | Check supported orientation; Form 4 is not larger on every axis |
| Monitoring | No camera listed in the comparison | 5 MP camera and remote images listed | Value it only when shared-machine or remote evidence reduces real labor |
| Best ownership case | Qualified installed workflow or deeply audited used value | Current professional throughput and workflow | Price the complete resin cell and accepted-parts-per-staffed-day result |
Use the current Form 4 review for the new-system case and the Form 3+ review for the legacy audit. If the standard Form 4 envelope is the constraint, compare Form 4 with Form 4L instead of forcing the upgrade around speed alone.
Source and scope: build volumes, published average speeds, print engines, and camera differences were rechecked August 27, 2026 against Formlabs' current Form 4 versus Form 3/+ comparison. These are manufacturer claims, not hands-on comparative throughput tests. Verify the exact resin, serial-number support, regional service, software, consumables, and post-processing fit.
Disclosure: GoodPrints may earn a commission from qualifying links on this page. This comparison uses current manufacturer-published specifications and claims; it does not claim hands-on testing.
Quick comparison
| Decision point | Formlabs Form 3+ | Formlabs Form 4 |
|---|---|---|
| Current purchase path checked Sept. 10, 2026 | Formlabs says new Form 3+ is no longer available in AMER; remaining Form 3-generation stock is expected through 2026 until depleted | Current Form 4 page retains a direct Buy Now route |
| Form 3-generation support horizon | User-replaceable spare parts through at least January 2027, with possible earlier item-level stockouts; consumables and customer support through at least January 2028 | Current-platform materials, consumables, and service path; verify the exact plan and region at checkout |
| Manufacturer-listed build volume | 14.5 × 14.5 × 19.3 cm; 4.05 L | 20.0 × 12.5 × 21.0 cm; 5.25 L |
| Published average print speed | 11 mm/hour across materials | 40 mm/hour across materials |
| Published speed range | 4-17 mm/hour depending on material | 15-100 mm/hour depending on material |
| Print engine | Laser and Light Processing Unit | Backlight Unit and LPU 4 |
| Remote visual monitoring | No camera listed | 5 MP camera; remote images and timelapses |
| Primary buying case | Verified legacy value or an existing installed workflow | Current professional throughput and workflow |
| Main overbuy or ownership risk | Cheap acquisition becomes expensive recovery | Premium workflow is unused by a light job queue |
Form 3+ support is a dated bridge, not open-ended parity
Current buyer gate: Formlabs' Form 3-generation support plan says new Form 3+ is no longer available in AMER and that remaining Form 3-generation products are expected to sell through 2026 only until stock is depleted. For an ordinary new purchase, Form 4 is the current direct path; a Form 3+ offer is a legacy or regional-stock decision that needs exact seller, region, warranty, return, and condition checks.
The same official plan says user-replaceable spare parts will be supplied until at least January 2027, while warning that individual parts may go out of stock sooner. It says resin tanks, build platforms, materials based on availability and demand, and customer support are intended to keep Form 3-generation printers operating until at least January 2028. Those dates support a bounded keep decision; they do not promise every resin, part, service tier, or replacement machine through the full window.
Recommendation: keep a qualified Form 3+ when its remaining job queue, critical spares, tanks, build platforms, resin path, backup plan, and planned retirement date all fit inside that support bridge. Buy Form 4 when the operation needs a current procurement path, longer planning runway, faster published workflow, or lower risk of a legacy component ending the cell early.
Official-source check: revalidated Sept. 10, 2026 against Formlabs' Form 3-generation support plan, current Form 4 page, and Form 4 versus Form 3/+ comparison. This is source-backed purchasing analysis, not a guarantee of future inventory or support.
Where Form 4 wins
Form 4 wins most new professional purchases because the upgrade case is operational. Formlabs says most prints finish in under two hours and publishes an average of 40 mm/hour across materials, compared with 11 mm/hour for Form 3/+. Those figures are manufacturer claims, not a promise for every geometry or material, but the gap is large enough to demand a queue-level test.
The platform also adds a camera for remote images, print history, and timelapses, plus a newer resin-handling and print-engine path. These features matter when several people share the machine, jobs have deadlines, or an operator needs evidence before walking back to the printer. Start with the Form 4 review and the Form 4 worth-it guide when current workflow is the main reason to buy.
Where Form 3+ can still make sense
Form 3+ can make sense as an already-owned machine with a qualified process, trained operators, compatible post-processing, and a stable material lane. It can also survive a used-buy audit when the purchase discount is substantial and the exact machine has documented condition and a realistic support path.
Do not treat the lower acquisition price as the full result. Ask for print history, maintenance records, included tanks and build platforms, current resin compatibility, software access, shipping protection, return terms, and a representative acceptance print. Confirm what Formlabs or a qualified reseller will support for that serial number and region. The Form 3+ review owns that deeper legacy-system check.
Run a ten-job throughput and fit audit
List ten representative jobs from the real queue. Record oriented part envelope, quantity, material, layer settings, support strategy, printer time, operator touch time, wash and cure time, finish requirement, inspection method, deadline, and the consequence of failure.
- Check oriented fit. Form 4 is not larger on every axis; use the actual supported orientation rather than comparing liters alone.
- Estimate accepted parts per day. Printer speed matters only after washing, curing, support removal, inspection, and reruns.
- Value the deadline difference. A faster printer is valuable when it shortens a design loop or prevents a missed production handoff.
- Measure operator intervention. Include setup, resin changes, cleanup, monitoring, documentation, and failed-job recovery.
- Repeat the test by material. Manufacturer-wide speed ranges do not replace a benchmark using the exact resin and representative geometry.
If Form 4 changes several current deadlines or produces materially more accepted output per staffed day, the upgrade has a measurable case. If the queue is light and Form 3+ already meets it, keeping a qualified system can be more rational than replacing it for specifications alone.
Used Form 3+ risk can erase the discount
A used professional printer is not automatically a bargain. Price the printer, freight, setup, tanks, cartridges, build platforms, wash-and-cure compatibility, facility controls, protective equipment, consumables, service, downtime, and the labor required to recover an undocumented process. Require a condition and acceptance plan before money changes hands.
A clean demo print is not enough. Use a part that exercises the intended material, height, supports, fine details, mating features, and finish. Define acceptance before the test. If the seller cannot provide a credible record or the machine cannot pass a representative job, the discount is speculative.
Build volume needs an orientation test
Form 4's listed 5.25 L build volume is about 30% larger than the Form 3/+'s 4.05 L. Yet the shape changes: Form 4 expands one planar dimension from 14.5 to 20.0 cm and Z from 19.3 to 21.0 cm, while the other planar dimension narrows from 14.5 to 12.5 cm. Long parts may fit Form 4 more naturally, while a specific square footprint can require a different rotation.
Export bounding boxes for the real supported orientations and add edge, support, and removal clearance. If standard Form 4 remains too small, compare Form 4 vs Form 4L rather than forcing a desktop machine to solve a large-format requirement.
Post-processing can remain the bottleneck
Faster printing does not guarantee faster finished parts. Washing, drying, curing, support removal, surface finishing, inspection, and waste handling may control the schedule. Map the complete resin cell and decide whether the current wash-and-cure capacity can absorb more printer output.
If the bench is not defined yet, read whether you need a wash-and-cure station and resin ventilation guidance. Follow the resin maker's safety documentation and applicable workplace and disposal rules.
Three buyer scenarios
A product-development team losing time to slow iteration
Choose Form 4 after a representative benchmark confirms that its faster print cycle shortens the full approved-part loop. Include queueing, wash, cure, inspection, and operator handoff rather than quoting printer speed alone.
A small shop offered a deeply discounted Form 3+
Consider it only if the exact region, condition, print history, included hardware, resin and tank path, service access, warranty or return rights, and an acceptance print are documented. In AMER, treat a new Form 3+ listing as remaining-stock or reseller inventory because Formlabs says its own new Form 3+ is no longer available there. Price critical spares before purchase: the published user-replaceable-parts horizon is January 2027 and individual parts may disappear earlier.
A hobby or occasional-use buyer wanting professional detail
Neither machine is automatically the best value. Compare the Form 4 vs Saturn 4 Ultra, Form 4 vs M7 Pro, and Form 4 vs GKtwo branches before paying for a workflow the queue will not use.
Before buying: prove the work belongs in-house
A Form 4 can be the stronger machine and still be the wrong business decision. Use the same ten representative jobs from the throughput audit to compare two complete paths: accepted parts made in-house and accepted parts supplied outside. Keep the file revision, material, orientation-sensitive features, finish, inspection, quantity, deadline, packaging, and approval state identical so the quote is testing the workload rather than a looser version of it.
| Choose this path | When it is the better fit | What must be proved |
|---|---|---|
| Own Form 4 | The queue is recurring, response time matters, and trained staff can keep the full resin cell productive. | Accepted output per staffed day, wash/cure capacity, inspection, safe handling, redundancy, and a defensible payback. |
| Keep Form 3+ | The installed process is qualified and still meets real deadlines without costly recovery work. | Condition, consumable and support access, representative-job capability, and the cost of remaining downtime. |
| Use outside production | Demand is occasional, unsettled, larger than the current cell, or expensive to staff and validate internally. | A scope-matched quote, sample or first article when needed, lead-time trigger, acceptance method, revision control, and repeat-order terms. |
Start with the buy-versus-print-service guide if ownership is still the real question. If dimensional or finish acceptance is unresolved, set the boundary with the resin tolerance guide, then use the small-batch service fit guide and ask JC Print Farm whether the job belongs in its current production lane. If the file, resin requirement, quantity, finish, acceptance points, and timing are already clear, use the quote-prep checklist, then send that exact packet through the quote intake. A useful outside quote should sharpen the ownership decision even when you ultimately buy the printer.
Final recommendation
Buy Form 4 for a current professional workflow when the ten-job audit proves that faster cycles, remote visibility, newer consumables, and lower process friction create measurable value. It is the stronger new-purchase default for most teams comparing these two generations.
Keep or buy Form 3+ only when its legacy value and exit plan are documented rather than assumed. An already-qualified machine can remain useful inside Formlabs' dated support bridge. A purchase must survive condition, regional availability, parts through at least January 2027, consumables and support through at least January 2028, possible earlier item-level stockouts, post-processing, labor, and acceptance testing. If it cannot, the lower acquisition price is not savings.
How much faster is Form 4 than Form 3+?
Formlabs publishes an average of 40 mm/hour across materials for Form 4 and 11 mm/hour for Form 3/+, about 3.6 times the listed average. That ratio is not a promise for every resin or part. Compare printer time, washing, curing, support removal, inspection, reruns, and operator touch time on a representative job.
Is Form 4 larger than Form 3+?
Form 4 lists 20.0 x 12.5 x 21.0 cm and 5.25 L, while Form 3/+ lists 14.5 x 14.5 x 19.3 cm and 4.05 L. Form 4 is larger overall and longer on X and Z, but Form 3/+ is wider on the other nominal planar axis. Test supported orientation rather than comparing liters alone.
When should a Form 3+ owner keep the old printer?
Keep it when the qualified resin lane, deadlines, accepted output, critical-spares plan, replacement-consumable access, backup capacity, and operator load fit the actual queue and a planned retirement date. Formlabs' current bridge points to user-replaceable parts through at least January 2027 and consumables plus customer support through at least January 2028, with availability caveats. Upgrade sooner when a representative benchmark proves Form 4 removes a recurring constraint or the legacy-risk window is unacceptable.
Frequently asked questions
Is Form 4 always faster than Form 3+?
Formlabs publishes much higher average and maximum print-speed figures for Form 4, but actual time depends on material, geometry, orientation, supports, and settings. Benchmark a representative job and measure the full finished-part cycle.
Does Form 4 have a larger build volume?
Yes in total listed volume: 5.25 L versus 4.05 L. The envelope is shaped differently, so check real supported orientation. Form 3/+ lists 14.5 cm on both planar axes, while Form 4 lists 20.0 by 12.5 cm.
Should I buy a used Form 3+?
Only when machine condition, print history, region, included hardware, critical-spares inventory, tank and resin access, service path, shipping, return terms, and a representative acceptance print are satisfactory. Formlabs says new Form 3+ is no longer available in AMER and publishes dated Form 3-generation parts and support horizons, so do not buy from acquisition price alone.
Should an existing Form 3+ owner upgrade?
Upgrade when repeat jobs show measurable deadline, throughput, monitoring, or operating-cost value. Keep the Form 3+ when it remains qualified, supported for the required workflow, and adequate for the actual queue.