Gemini 2.5 Flash vs Gemini 3.1 Pro Preview: API price and specs

Gemini 2.5 Flash is 85% cheaper than Gemini 3.1 Pro Preview on input price.

Gemini 2.5 Flash is 79% cheaper than Gemini 3.1 Pro Preview on output price.

Gemini 2.5 Flash is 82% cheaper than Gemini 3.1 Pro Preview on a 1M-in / 200k-out workload.

Gemini 2.5 Flash has a 1.6% larger context than Gemini 3.1 Pro Preview.

Field	Gemini 2.5 Flash	Gemini 3.1 Pro Preview
Lowest input, per 1M	$0.15	$1.00 +566.7%
Median input, per 1M	$0.30	$2.00 +566.7%
Lowest output, per 1M	$1.25	$6.00 +380%
Median output, per 1M	$2.50	$12.00 +380%
Lowest unit price	—	—
Cost of 1M in + 200k out	$0.40	$2.20 +450%
Context	1.1M	1M +1.6%
Max output	66K	66K
Providers	26 +7.1%	28
Regions	EU, GLOBAL, US	GLOBAL, US
Accepts	application/pdf, audio, audio/aac, audio/aiff, audio/alaw, audio/flac, audio/l16, audio/m4a, audio/mp3, audio/mpeg, audio/mulaw, audio/ogg, audio/opus, audio/wav, audio/webm, file, image, image/heic, image/heif, image/jpeg, image/png, image/webp, pdf, text, video, video/3gpp, video/avi, video/mov, video/mp4, video/mpeg, video/mpg, video/webm, video/wmv, video/x-flv	application/pdf, audio, audio/aac, audio/aiff, audio/alaw, audio/flac, audio/l16, audio/m4a, audio/mp3, audio/mpeg, audio/mulaw, audio/ogg, audio/opus, audio/wav, audio/webm, file, image, image/heic, image/heif, image/jpeg, image/png, image/webp, pdf, text, video, video/3gpp, video/avi, video/mov, video/mp4, video/mpeg, video/mpg, video/webm, video/wmv, video/x-flv
Returns	text	text
Type	Text models	Text models
Free option	no	no
Cheapest provider	kilo	kilo

Your own workload: how many tokens the model gets (input) and gives back (output) - for example, in a month. The "Cost" row of the table above is recalculated for these numbers, for each model.

Computed from current offers each time the page opens; the best value of a row is bold, the percent is how far behind the best.

Providers selling both

302ai, abacus, aihubmix, aiml, deepinfra, edenai, fastrouter, google, google-vertex, helicone, impossibl, jiekou, kilo, meganova, ofox, openrouter, orcarouter, perplexity-agent, poe, requesty, standardcompute, trustedrouter, vercel, zenmux

Frequently asked questions

Which is cheaper, Gemini 2.5 Flash or Gemini 3.1 Pro Preview?

Gemini 2.5 Flash is 85% cheaper than Gemini 3.1 Pro Preview on input price. Gemini 2.5 Flash is 79% cheaper than Gemini 3.1 Pro Preview on output price. Gemini 2.5 Flash is 82% cheaper than Gemini 3.1 Pro Preview on a 1M-in / 200k-out workload.

Which has the larger context, Gemini 2.5 Flash or Gemini 3.1 Pro Preview?

Gemini 2.5 Flash: 1.1M tokens; Gemini 3.1 Pro Preview: 1M tokens.

Where can I use both Gemini 2.5 Flash and Gemini 3.1 Pro Preview?