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Short answer: H4 and 9003 are names for the same kind of dual-beam bulb, and they are usually treated as the same socket. PIAA lists the H4 as similar to the US HB2 (9003), and Osram lists its H4 on a P43t base at 60/55 W. Sources disagree on whether the two are built to identical tolerances, so check the lens marking and the approval required in your market before you list an H4 LED bulb as a 9003 fit.
Key takeaways
- H4 is the ECE name; 9003 is the US trade number; HB2 is the US designation used on lamp lenses.
- PIAA lists H4 as “similar US bulb: HB2 (9003)”, with 2 filaments at 60 / 55 W.
- Osram lists the halogen H4 at 60/55 W, 1650/1000 lm, on a P43t base.
- Retail guides say “identical”, while forum posts claim tighter tolerances for 9003; no manufacturer page we opened settles it.
- TUHO’s product pages list H4 as the dual-beam socket and do not name 9003 or HB2, so confirm the fit with the supplier before labeling.
Is H4 the same as 9003?
Yes, for most buying purposes H4 and 9003 are the same dual-beam bulb under two names. The names come from two systems: H4 from the European (ECE) system and 9003 from the US trade numbering.
- PIAA: Its cross-reference lists the H4 with 2 filaments and “6 V & 12 V: 60 / 55 W”, with the note “Similar US bulb: HB2 (9003)” (PIAA cross-reference).
- Osram: Its ORIGINAL LINE H4 (order reference 64193) is a 12 V lamp at 60/55 W on a P43t base in ECE category H4 (Osram ORIGINAL LINE H4).
- Word of caution: PIAA says “similar”, not “identical”, and tells buyers to always check wattage before substituting.
What do H4, 9003 and HB2 mean?
They are three labels for the same family, each used in a different place. The table shows where each label appears.
| Label | System | Where you see it |
|---|---|---|
| H4 | ECE category | Bulb packaging and European lamp markings; Osram lists ECE category H4 |
| 9003 | US trade number | US bulb charts and retail listings |
| HB2 | US HB type | The mark on a US-market headlamp lens |
On a US-market lamp, FMVSS No. 108 requires the lens to carry the HB type in front of each replaceable light source, so the mark to look for is HB2 (49 CFR 571.108). The rule names the HB type, and PIAA supplies the link between HB2 and 9003.
Is there any real difference between H4 and 9003?
The sources do not agree on whether there is a difference in build tolerances. Retail guides say there is no difference beyond the name, while some forum posts say the US rules require tighter filament positioning for the 9003.
- Same socket family: PIAA and Osram both point to a two-filament bulb at 60/55 W; Osram lists the P43t base.
- Tolerance claim: Some forum posts say the US rejected the original H4 tolerances, so 9003 bulbs must meet tighter specs. We found no manufacturer or regulator page that states this, so treat it as unconfirmed.
- Approval: The legal question is not the name but the approval the product carries for your market. A bulb marked for ECE use is not automatically approved for US road use, or the reverse.
The practical answer is the same: match the lamp’s marking and buy a bulb approved for that market, and do not assume two bulbs are identical because the names match.
Can you fit an H4 LED bulb in a 9003 headlamp?
An H4 LED bulb can fit a 9003 headlamp socket if the product is made for that socket, but the supplier should confirm it, and the beam still has to be checked. The LED chips must sit where the two filaments sat, or the low beam and high beam scatter.
- Check the lens: On a US-market lamp, look for the HB2 mark.
- Check the bulb list: Find H4 or 9003 in the owner’s manual.
- Check the space: Many H4 lamps have a dust cover and little room; see our H4 LED headlight bulb guide for heat and clearance.
- Test both beams: Check the low and high beam against a wall, and re-aim if needed (see how to aim headlights).
What does TUHO list for H4 LED bulbs?
TUHO’s H4 category lists 14 models, and each model page lists H4 as a dual-beam socket. The pages do not name 9003 or HB2 as sockets, so a seller serving 9003 lamps should confirm the fit with TUHO in writing.
| Model | Listed lumens per set | Listed power per set | Voltage | Canbus |
|---|---|---|---|---|
| Z2S | 3300 LM | 33W-20W | 6-32V | Canbus-ready, no polarity |
| V28 | 6000 LM | 65W-52W | 9-60V | Not listed |
| V25 | 8000 LM | 55W-50W for H4 | 9-32V | Canbus-ready |
| S01-H4 | 6000 LM | 64W | 9-32V | Not listed |
| X02 | 20000 LM | 200W | 9-60V | Not listed |
These are five of the 14 models, shown as the product pages list them. Every figure is for one set, a pair of bulbs, and is a catalog value, not a test result. See the full H4 category for the rest.
What should distributors do about the H4 and 9003 labels?
Label the product with the name your market uses, and keep the other names in the listing so buyers find it. The wrong label is a common source of returns.
- EU and most export markets: Use H4 as the main name.
- US market: Use 9003 / HB2 as the main name, and show H4 as the equivalent.
- Ask for the fit statement: Get the supplier’s written statement that the H4 version is intended for 9003 / HB2 lamps.
- Do not claim approvals: State DOT or ECE approval only if the supplier gives you the document for that model and order.
- Keep the dual-beam warning: H4 and 9003 are dual-beam bulbs; do not mix them up with single-beam sockets such as 9005 or 9006. See our guide on 9005 vs 9006.
How TUHO supplies this category
TUHO Lighting is an automotive LED lamp manufacturer in Dongguan, Guangdong, and it lists its H4 models in the H4 LED headlight bulbs category.
- OEM and ODM: TUHO supports OEM and ODM projects; see the OEM/ODM page for the order process.
- Custom branding: Custom logo, color box and outer carton are supported, so the box can carry the H4 / 9003 labeling your market uses.
- Mixed orders: Small batches and mixed-SKU orders are supported.
- Lead time: Delivery is usually arranged within 1-10 working days, depending on quantity. Minimum quantities and prices are confirmed per order.
- Documents: Products are matched to the destination market’s rules, and the required documents are confirmed per model and per order.
Sourcing H4 / 9003 LED headlight bulbs for your range? Send us your sockets, vehicle markets and target quantity. TUHO can quote OEM/ODM orders with custom logo and packaging, mixed SKUs, and samples for testing. Request a quote
FAQ
Is H4 the same as 9003 and HB2?
H4 is the same family of dual-beam bulb as 9003 and HB2. PIAA lists the H4 as similar to the US HB2 (9003), so match the lens marking and the approval for your market.
Can I use an H4 bulb in a 9003 socket?
You can usually use an H4 bulb in a 9003 socket, because they are treated as the same dual-beam socket. Confirm with the bulb maker and check the HB2 lens mark and the approval required in your market.
Is 9003 high beam or low beam?
The 9003 is both, because it is a dual-beam bulb. PIAA lists the H4 with 2 filaments, one for each beam.
Is 9003 the same as 9006?
No, 9003 is not the same as 9006. The 9003 is a dual-beam bulb with 2 filaments, while the 9006 (HB4) is a single-filament bulb at 51 W in PIAA’s list.
Do I need a Canbus decoder for an H4 LED bulb?
Only some cars need a decoder with an H4 LED bulb. V25 and Z2S are listed as Canbus-ready; see our Canbus guide for when it matters.
Bottom line: H4 and 9003 (HB2) are two names for the same family of dual-beam bulb. Buy by the lens marking, the market approval and the supplier’s written fit statement, not by the name alone.
Editorial note: Halogen figures come from Osram’s ORIGINAL LINE H4 catalog page and PIAA’s cross-reference page, both read on 26 October 2026, and the lens-marking rule from the eCFR text of 49 CFR 571.108. TUHO model figures were read from the live product pages on 26 October 2026 and are catalog values, not independent test results. Claims about differing tolerances come from forum posts and were not confirmed by a manufacturer or regulator page. This article does not say that any bulb meets DOT, ECE or any other approval.
