ERNIE 5.5 Flash Preview vs ERNIE 5.1
Official Baidu ERNIE API prices and LMArena scores, checked 2026-11-14. Add up to 2 more models to compare 4.
ERNIE 5.5 Flash Preview costs less; quality is n/a.
ERNIE 5.5 Flash Preview is 2x cheaper on input and 2.2x cheaper on output. LMArena has no task both models are ranked on, so quality is n/a here. ERNIE 5.5 Flash Preview has the longer context window (1M vs 128K tokens). A medium month (20M input + 5M output tokens) costs $11.25 on ERNIE 5.5 Flash Preview and $23.85 on ERNIE 5.1.
- Pick ERNIE 5.5 Flash Preview if you want the lower bill ($11.25 vs $23.85 for a medium month) or you need the 1M context window.
- Pick ERNIE 5.1 if nothing here clearly favors it (no lower bill, bigger context, cheaper cache or LMArena lead of 3+ points over ERNIE 5.5 Flash Preview).
Medium: 20M input + 5M output tokens a month at list price (short-context rate, no caching or batch discounts).
Marked side is better: lower for prices, higher for context and scores. Bars are scaled to the larger of the two.
| Spec | ERNIE 5.5 Flash Preview | ERNIE 5.1 |
|---|---|---|
| Price per 1M tokens | ||
| Input | $0.28 | $0.56 |
| Cached input | $0.028 | None |
| Output | $1.13 | $2.53 |
| Blend 3:1 | $0.4925 | $1.05 |
| Sample month, medium | $11.25 | $23.85 |
| Context | ||
| Context window | 1M tokens | 128K tokens |
| Quality (LMArena, out of 100) | ||
| Coding | Not ranked | Not ranked |
| Chat | Not ranked | 0/100 #25 of 54 |
| Creative writing | Not ranked | 0/100 #32 of 54 |
| Roleplay and characters | Not ranked | 0/100 #24 of 54 |
| Reasoning and math | Not ranked | 9/100 #25 of 52 |
| Vision | Not ranked | Not ranked |
| Long documents | Not ranked | Not ranked |
| Cheap bulk and agents | Not ranked | Not ranked |
| Details | ||
| Provider | Baidu ERNIE | Baidu ERNIE |
| API model id | ernie-5.5-flash-preview | ernie-5.1 |
| Notes | Preview released Nov 11, 2026. 280B total, 14B active parameters. Baidu says Apache 2.0 open weights are coming. | Prompts up to 32K. Prompts of 32K to 128K cost $0.84 in, $3.10 out. |
| Sources | ||
| Last checked | 2026-11-14 | 2026-11-14 |
| Official pricing | Baidu ERNIE pricing | Baidu ERNIE pricing |
Plans from data checked hourly against each vendor's official pricing page. Vendors state limits in different units, so we quote them as published. Team and enterprise plans are per seat.
API prices in USD per 1M tokens from each provider's official pricing page. Blend 3:1 = (3 x input + output) / 4. Sample month = stated input and output tokens at the list price, no caching. Quality: relative score out of 100 on each LMArena leaderboard (100 = top model we price on that board, n/a = not ranked there), data licensed CC BY 4.0. See how we pick.
Where each one ranks on LMArena
Relative score out of 100 on each leaderboard (100 = the top model we price there), with the rank among the models from our API price table that appear on that board.
- Coding (Code Arena): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 not ranked
- Chat (Text Arena): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 #25 of 54 (0/100)
- Creative writing (Text Arena creative writing): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 #32 of 54 (0/100)
- Roleplay and characters (Text Arena multi-turn): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 #24 of 54 (0/100)
- Reasoning and math (Text Arena math): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 #25 of 52 (9/100)
- Vision (Vision Arena): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 not ranked
- Long documents (Document Arena): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 not ranked
- Cheap bulk and agents (Agent Arena): ERNIE 5.5 Flash Preview not ranked, ERNIE 5.1 not ranked
Pricing details from the official pages
ERNIE 5.5 Flash Preview lists $0.28 input, $1.13 output, $0.028 cached input per 1M tokens on Baidu ERNIE pricing. ERNIE 5.1 lists $0.56 input, $2.53 output per 1M tokens on Baidu ERNIE pricing. Prices checked 2026-11-14.
- ERNIE 5.5 Flash Preview: Preview released Nov 11, 2026. 280B total, 14B active parameters. Baidu says Apache 2.0 open weights are coming.
- ERNIE 5.1: Prompts up to 32K. Prompts of 32K to 128K cost $0.84 in, $3.10 out.
Sample monthly bill at list price, no caching: Light (2M input + 0.5M output tokens): $1.12 vs $2.38. Medium (20M input + 5M output tokens): $11.25 vs $23.85. Heavy (200M input + 50M output tokens): $112.50 vs $238.50.
FAQ
Is ERNIE 5.5 Flash Preview cheaper than ERNIE 5.1?
ERNIE 5.5 Flash Preview costs $0.28 input and $1.13 output per 1M tokens; ERNIE 5.1 costs $0.56 and $2.53. For a medium month (20M input + 5M output tokens) ERNIE 5.5 Flash Preview is cheaper: $11.25 vs $23.85.
Which is better for coding, ERNIE 5.5 Flash Preview or ERNIE 5.1?
Code Arena score: ERNIE 5.5 Flash Preview n/a (not ranked), ERNIE 5.1 n/a (not ranked). We do not guess missing scores.
Which has the bigger context window?
ERNIE 5.5 Flash Preview: 1M tokens. ERNIE 5.1: 128K tokens.
How much do ERNIE 5.5 Flash Preview and ERNIE 5.1 cost per month?
Light (2M input + 0.5M output tokens): $1.12 vs $2.38. Medium (20M input + 5M output tokens): $11.25 vs $23.85. Heavy (200M input + 50M output tokens): $112.50 vs $238.50. Pick your own token counts in the plan vs API calculator.
Where do these numbers come from?
Prices come from each provider's official pricing page, checked daily. Quality is the relative score on the LMArena leaderboard dataset, licensed CC BY 4.0. Where a model is not ranked we show n/a.